Has anyone sampled different car audio set ups to gauge whether there's a difference in audio quality between inputting your ipod into a faceplate (JVC) mini-to-mini, into a RCA adapter cable out of the back of a unit (Alpine/Pioneer) or using an iPod specific adapter cable (that also recharges)? I used a Belkin Auto charger with line out & volume control which worked quite well with my cassette adapter & would use the line out from it with whatever new set up I chose (except the ipod specific one).

The JVC model w/ Aux In on faceplate seems like the easiest/cheapest option, however if using an RCA adapter cable out the back (i.e. on the Alpine or Pioneer) gives a better sound quality I'd go with that option. I'd prefer using the iPod to control the music, rather than a car stereo, but if there's a difference in sound quality, I would opt for the iPod specific adapter (using line out & recharging).