Sure the little XM and Sirius plug and play units are cheap, work well, and are portable in most cases. But unless you want to spend two to three times what the unit cost for a pro installation, most units just get stuck to the dashboard with wires all over the place. Well, Bob Loblaw is here to help, and he happens to have installed a Roady 2 in his trusty subaru, but the general ideas will carry over to many other cars. But Bob does not know why you would want anything other than a subaru. Or a porsche. If you have a porsche, get a professional installation. Or better yet, turn off the radio and listen to the engine. Unless it's a 924. Or a 914. Bob digresses.
Since Bob did this project before learning of instructables from one of his clients looking to reattach a severed hand (long story), he neglected to document the individual steps, but since the setup is removable from the car, he will give a quick step by step on how it's done.
Step 1: Ingredients
To start with, there are two lines running to the XM unit: power and the antenna. The music is broadcast over the FM radio, so no tape adapter or direct audio connection to the head unit. The trick is to hide the cables and provide a secure mount for the xm unit, while still allowing for the unit to be removed from its base to prevent theft or to use it elsewhere. Bob elected to use the ashtray of his car as the mounting base, because it's an easily replaceable and relatively inexpensive part. It's also easy to remove and drill through.
What you'll need:
drill & bits
1" or so corner braces (x2) ($3 for 4 at Ace H'ware)
Nylon spacers, about 1" (x2)
A pair of long bolts and lock nuts
a piece of flat metal
JB Weld (of course)
some small zip ties
file or grinding wheel
Step 2: Fitting It Together
This process takes some trial and error:
Remove the ashtray and take the XM mount (the black plastic thing that the radio mounts to). You will need to unscrew the ball joint so that all you have is the black rectangle mount with a threaded plastic stub out the back. In order to have the XM mount fit at an angle against the ashtray, the threads will need to be ground down using a file or grinding wheel. The angled mount is so you can see the radio from a regular driving position. I'd say about 20-30 degrees is what Bob Loblaw ended up with. Bob tried to grind the threaded portion so it would fit flush with the ashtray, but it didn't work, nor would it add any real benefit, so you should probably just grind it all the way down.
Next, you'll need to mount the XM backing to the ashtray. To do this, drill two holes through the ashtray as that will allow the two long bolts to fit through. Bob drilled these holes at an angle using a drill press to aid with the viewing angle. The bolts should be spaced within the width of the XM backing width, as they will provide the support. With the bolts extending out the bottom of the ashtray, slide the nylon spacers on and then put the corner braces on. Depending on how the braces look, they may need to be bent in order to get a better viewing angle. The goal here is to have the top of the xm unit fit almost flush with the dashboard. Once you have it where you want it, bolt down the corner braces with a piece of metal spanning between the two bolts for additional support.
JB Weld the XM backing to the corner braces. During all this, you'll need to ensure no parts interfere with getting the ashtray in and out of it's receptacle (on Bob Loblaw's car, he has to put the shift lever in neutral to be able to fit the ashtray in and out).
Step 3: Contain the Wires
If you've made it this far, you're almost done. Now to get the loose wires under control. The power cord is the main one to deal with on the dash, while the antenna wire just gets tucked under any available surface with a fat flathead screwdriver. For this installation Bob went all out, and used a drill bit to grind away a notch on either side of the top of the ashtray so that it would open and shut fully without hitting the wire entering and exiting. The wire was coiled up and two holes were drilled at the wire entrance (top right side of ashtray) in the center bottom of the ashtray, and at the wire exit (top left side of ashtray). Bob used small zip ties to pin down the wires at each spot, and then a dab of JB Weld at each notch where the wire enters and exits the ashtray. Bob made sure the minimum length of the power cord extended from the left side of the ashtray to keep things neat.
Step 4: Wrap Up
Run the antenna wire as you see fit. Bob placed his on the roof of the car, as close as possible to the car's antenna to give better reception using the fm modulator of the Roady 2. Check the JB weld on the bracket occasionally as frequent hot and cold can sometimes cause it to come unglued. Use a two part epoxy for a really strong bond. Now, just tune in to your favorite station and enjoy. Oh, you liked opie and anthony? Undo steps 1-4 and post your childlike video of your radio smashing to youtube.