Step 1: What you'll need
iPod touch/iPhone clip.
(I purchased this in the mall at one of those booths that sell cellphone accessories.) Cost $11. This was my main purchase.
Thin, pliable piece of metal. I took mine off the back of an old hard drive.
Two nuts and bolts
Two self taping screws
Thin foam (optional)
Oh, and a car. Preferably one of the ones mentioned previously.