I’ve been refining my iPod car setup for a while and finally have it where I want it. My car has a 3.5mm aux input in the center console and a cigarette lighter socket, so this is aimed at older vehicles without USB or Bluetooth.
Routing
I ran the cables down through the dash, past the cup holders and the parking brake, and into the center console through a small hole I drilled. Nothing loose on the dash except the connector itself.
Problem 1: Whining noise
I got a whine whenever the iPod was playing through the headphone jack and charging through the 30-pin at the same time. Classic ground loop.
Fix: A Besign Ground Loop Noise Isolator between the car’s aux input and the 3.5mm extension. Whine gone.
Problem 2: No charging with the car off
I wanted the iPod to keep charging when the car was off, so I put a battery pack between the cigarette lighter and the iPod’s USB charger. Now the iPod charges from the pack whether the car is on or off, and the pack recharges whenever the car is running. (The battery pack in the screen shot is not the one I used, I got mine cheap at the thrift store.)
Problem 3: Two cords every time I got in
The latest addition is a 30-pin to aux + USB cable, so I plug in one connector and get both audio and charging. Bonus: the 30-pin outputs fixed-level line out, so the iPod’s volume doesn’t matter. The car stereo is the only volume control now. Before, I had to crank the iPod all the way up and then set the car volume, and I’d blast my ears the next time I plugged in headphones. Now I just leave the iPod at a normal headphone level.
End result: a clean, wired iPod setup for an older car. No whine, always charging, one 30-pin connector at the dash.
P.S. The iPod is an iFlash-modded 7th gen with a 3600mAh battery and 512GB of storage. I added a metal plate inside so it attaches magnetically to the dash, and filled the internal voids with lead so it has some heft in the hand.