-This instructable requires some knowledge of electronics and auto body assembly.
-This might involve taking apart large sections of your car's console, if this could void a warranty, do so at your own risk.
-In some states and municipalities, it is illegal to have non-signal lights on while your vehicle in motion. Check with your local authorities before using on the street.
Time: 3-6 Hours
Cost: $20-50 (depending mainly on how many lights you get)
Difficulty: Decently easy
Step 1: Gather materials
-One or several waterproof, 12V LED strings - $10 ea.
-Lots of wire. Two-strand polarized wire is great (red-black or white-black)
-SPST switch - Free-$3 (I got a lit-when-on one)
-555 timer - $0.10-$1.50 if you went to Shady-o Rack
-10000-15000 uF worth of 10v capacitors (you can string them in parallel to add the capacitance)
-15kOhm resistor - the bigger the resistor the slower the pulse - alternatively you can use a potentiometer
-Project box of some sort
-Scrap thin medium-density fiberboard (MDF) or sheet metal
-Soldering iron and solder
-Hot glue gun
-Various size drill bits
And of course a car. It's a good idea to know your way around the inside of your car a bit before beginning.