Picture of ElectroLuminescent Bumper Sticker
[Featured in the February 4th Newsletter]

As you folks know by now, I am a Geek (and proud of it)
who has added a computer to my car;
Today I am going to show you how to take EL panel from a tee shirt
and convert it and install on your car as a EL Bumper sticker
and geek out your ride.

I predict that  EL bumper stickers will become popular in a year or two

WOW - Gizmoto featured me!

Now EnGadget!!

I'm being picked up by alot of tech blogs!

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Step 1: The Materials

Picture of The Materials
I was looking thru a geek gear catalog and came upon this tee shirt
(best price $19 with free shipping)

you also need some double stick tape for fabric (sold at craft shops)
a 12v to 5v USB car adapter and some industrial double stick foam tape
(we ALL have that already!)

12v access in the back of your car (ignition switched power is best)

The design is animated, and shows Wi-Fi signal around the area
the less wi-fi the less bars display, also no wi-fi will turn the tower icon off

Here is a link to the shirt animated

Step 2: Building the Power Supply (part 1)

Picture of Building the Power Supply (part 1)
The unit is powered with three AAA batteries (4.5v) so I am pulling out the battery
compartment and incorporating a 12v to 5v Power converter (any USB power outlet will do)
adding leads to attach to my tail lights (so it lights up only at night)

Here is the case opened up (Picture 2)
I removed the EL power supply (Picture 3)
and snaked the 5v power leads into the battery compartment (picture 4)

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Adam12hicks2 years ago
This is really cool. Maybe I'll leave my T-Mobile hotspot always on, put a sticker above it that says Free WI-FI and let anyone connect who happens to drive next to me :-)
geeks rule wooh!!!!!!!!!!!!!!
These panels are sold at for $12 no need to buy the shirt and the try to get the panel out.
macgeek (author)  Light_up_shirt4 years ago
actually your price is $17.00 the same price I paid for the panel and the shirt.

Mega1mpact4 years ago
epic licence plate.
 You, sir, are an inspiration.  I'm blatantly ripping off your idea, but the vehicle I'm installing in is a Toyota Tacoma.  My shirt is in transit from ThinkGeek, my soldering iron is at the ready, and I'll steal some fabric tape from the wife.  I'll have the nerdiest truck in Maine, that's for sure :)
macgeek (author)  james.c.obrien5 years ago
and I hope YOU POST PICTURES!!!!!


 Will do.  Quick question, though - does/did your t-shirt power supply (pre-hardwire, mind you) emit a high-pitched tone?  Mine does, and it seems to change pitch with the strength of the signal displayed.  Odd...I shouldn't hear it in the car, but still.
macgeek (author)  james.c.obrien5 years ago
yea, it does have a high pitched tone, if its in the back of the car the ambient road noise hides it.

it's annoying for about 5 minutes, then it blends in with the other noises.
(just like me!)

Woot! More maine people on instructables.
Im curious as to how one would go about learning how to wire it like you did but for my car. I have a GMC 2010 Terrain. Are there wiring information one can find online or do you need to just go in there and check it out for yourself?
shanty18124 years ago
very nice!! i ll try it in my mitsubishi L200
junits154 years ago
ItzMeLogo4 years ago
 I have a stupid question, does it actually work to producing efficient enough wifi? if so does it work while driving or running the engine/accessory power?
articice5 years ago
why-fry destroys your geeky brains, don't you know that?
kgettys5 years ago
Thank you for the instructions! I made a few changes for my situtation. First I used 3 half inch double sized tape squares. I put the decal on the window behind the driver seat. This way the cord reaches the cigratte ligter port on the dash board. I use an 5v a/c adapter that plugs right into the power supply box that came with the decal. The a/c adapter is plugged into a power inverter that is plugged into the power supply. I then bought a DLink access point that plugs into the USB port of my laptop for power. The access point broadcasts a WIFI signal that keeps the decal alive. I park my car in front of my local Mcdonalds (that does not have a hot spot or any nearby). I also have an empty computer monitor mounted on the back of my car with the guts removed and a "Computer Repairs" sign where the screen was. That gets a lot of attention and with the decal animated at night, even more. Especially between 7 and 9 pm when people are using the Redbox to return their DVDs! On the inside deck behind the rear window (to the left of the monitor), I have an red LED sign that scrolls a "Computer Repairs" and my phone number too!
bazery5 years ago
 I'm from Ireland so this might blow some people minds....but just a quick question, does this wire into your lights or did you wire it back to the usb power adapter?
macgeek (author)  bazery5 years ago
it's wired into my lights.. and no that doesn't blow any minds
(or fuses)


GYNot5 years ago
The guy at my local auto parts placed looked at my head askew when I asked for a 12v to 5v converter. I'm guessing yours had some other purpose in life.  Was it built for some other purpose in life?
macgeek (author)  GYNot5 years ago
Poor auto guys, they don't have two brain cells to rub together.

ANY Cell phone charger will do, the cheaper the better
a 12V "USB" plug will also do
Mr.NHRA macgeek5 years ago
 I am an auto guy and yeah most of the time all they know how to do is turn wrenches but if that were true all the time I wouldn't be looking at this. This is like the COOLEST thing I will ever do to my car. 
macgeek (author) 5 years ago
I re-did the Bumper Sticker to be Just that a Bumper Sticker,
Here is the link:
Sarek5 years ago
Thanks for the quick reply Jonathan. This is a tad off topic, I have an aftermarket car stereo and its remote that uses 2 AA batteries.

My car (honda S2000) has an OEM unit that controls the OEM radio on the dash. There is a kit out that let's me wire my remote to the dash controls but I have to keep changing the batteries as needed.
Is it possible to use the same solution that you though of to also hard wire my car stereo remote to the car (ie parking lights)?

Thanks in advance for any info...

HAHAHA and I'm not quite forty... yet ;-)
macgeek (author)  Sarek5 years ago
if the buttons are on your steering wheel that may be complicated
the only real power usually to the steering column is a horn and maybe
a airbag control, both very critical and not to be mucked with.

maybe rechargeable batteries are a better solution?

Sarek macgeek5 years ago
That is very true. Sorry I wasn't clear before. Unlike other OEM radio controls that are located on the steering wheel, the S2k is on the dash left side by the start button..
link to pic

because I'm a noob to electronics, my main concern was if it's the correct "converter" for the 2 AAA baterry remote. (I stated AA earlier which is incorrect, sorry)

Crucio Sarek5 years ago
2 x AAA (or AA or C or D) yield about 3V as each is 1.5V.  A car's battery gives 12V and USB gives 5V.  You need something (a regulator or transformer) to reduce the car's 12V or USB's 5V down to 3V before you can use the car's power to substitute away your batteries.

This may not be the project for you if you're not sure how to do the above.  But if you can find an electronics buddy, this is easily do-able.  I'd say the hardest part will be taking down your dash to tap into the right power wires.  Rather than using the the running lights, it's probably best to tap into the stereo power cables.

An easier alternative, with very good results, is to convert the system to use D-cells.  You can do that by installing AAA pass-through blanks that connect to a D-sized battery holder pack, which can be installed out of sight.

AAA batteries have about 1250 mAh of capacity, while D cells have about 20500 mAh.  So a single D cell will last longer than 16 AAAs.  That effectively eliminates the battery replacement pain.

Sarek Crucio5 years ago
Great info! Thank you very much for taking the time to respond. I will try the D-cell option. At least I wouldn't have to worry about it for possibly 2-3 years at a time. :D

Thanks again Macgeek and Crucio!

Hey Sarek, try using a usb car adapter. I bought one of ebay real cheap for my ipod. But I can also plug anything that runs off usb into it.
macgeek (author)  Crucio5 years ago
its 3 AA batteries (4.5v) - The .5v voltage difference is minor,
and it works perfectly.

Crucio macgeek5 years ago

Sarek's application uses 2 AAA's.  See his comments, above.

elbie21695 years ago
Nice instructable. Very cool.

However, being involved in Law Enforcement, my first thought was "Why would I want to advertise to thieves that I have a computer in my car?" Nothing like driving around with a nice sign that says “rob me!” That being said, I’ll probably try to make this thing. I’ll just put it somewhere a little more private.
macgeek (author)  elbie21695 years ago
I'm going to post some daylight pictures of it.
To be really honest during the day it looks like a sticker.
very plain. - If you look at my car it really almost looks like a 'stock'
honda, even if you look inside the car the only 'giveaway' there is anything
of 'value' in the car is the USB keyboard.

I own a 2007 Honda element and I live in Brooklyn NY,
the car has been broken into once, and that was because of my own
stupidity / carelessness.

I had left a garmin GPS receiver stuck on the front window.
They smashed the side window and took the GPS, everything else,
the Mac Mini, the in dash screen (was docked so it was just a black box)
and the assorted tech that was in the car was ignored.

I will post pictures, that will say it all.

kmpres macgeek5 years ago
When I was in my 20s I lived in NYC, too.  Had a new 1984 VW Rabbit that I loved and modified heavily to serve my geeky bachelor needs.  Then the Blaupunkt stereo/cassette player got stolen, and six months later, its replacement got stolen.  This was getting really old so I scrounged some used Centronics dot-matrix printer parts (remember those?) from my employer and built an automatic retracting device that pulled the radio inside the dash when the engine was turned off.  A cheap plastic panel, hinged just over the stereo and attached to it with a piece of elastic, automaticaly covered up the hole in the dash where the radio was. 

Worked like a charm.  Nobody touched my radio until the day I sold the car six years later.  Should have patented that device as nowadays nearly all cars have something like it.  All this is to say that I'm right there with you with your need to make mods to keep your in-car stuff from being stolen.

By the way, you know the old joke about:  Where do you put your trash during a NYC sanitation strike?  You gift-wrap it and put it in your car.  Something to think about.
anupam5 years ago
everything bought!!!whats been made by self??
macgeek (author)  anupam5 years ago
that's like saying
I bought flour, baking soda, yeast, and sugar.

so you bought me a cake.

Pretty darned amazing.

Please help me understand a couple of things about your Instructable:

1. Are you really able to catch an occasional Wi-Fi signal while cruising town? If so, how often and is the signal strength sufficient to use the Wi-Fi?

2. What is the essence of the display from the T-shirt? I don't understand that at all.

3. Is there a correlation between an actual signal and the movement of the )'s around the tower icon? Or is this just random?

To some of you, the questions I'm asking may seem stupid but HEY, I'm 60 years old and trying to keep up with what's goin' on. Try doing that when all your friends don't have a clue and could care less!!!  LOL  (funny, but true)

This instructable is cool but has me somewhat baffeled .

Grand Rapids, MI
macgeek (author)  ForgetMyProfile5 years ago
Robb, there are no stupid questions, only people too arrogant to answer them


1 - Yes, you would be amazed how many OPEN wi-fi networks there really are
2 - The tee shirt (like the bumper sticker) is mainly Eye-candy, geekchic
     (the actual USE of it is really minimal, esp if your driving)
3 - Yes, the better the signal the more bars show (just like those AT&T commercials)

Thanks Jonathan,

I appreciate the pep talk about stupid questions. I'm just trying to keep up.

I still don't understand what part the T-shirt plays in the scheme of the project..

Tell me about the tee shirt. What lights up on the T-shirt? Is it LED, neon, some kind of  phosphorized or luminescent paint? Is the T-shirt made to do something specific. If so, how so?

 I scrolled up and down looking for the blanky-blank receiver that detects the wifi  signal used. The receiver along with the display are part of the removable"decal" that comes with the shirt.  Respectfully macgeek no one should have been required to read a product detail on a separate page from the instructable to learn that. 
macgeek (author)  ForgetMyProfile5 years ago
the tee shirt has a EL (Electroluminecent) panel that is animated with a Wi-Fi logo and
as it detects wi-fi it's bars increase (showing signal strength)

( ilove wikipedia!)

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