Medyo pihikan ka ba when it comes to sound quality?
Well, let me share some results from my experiments.
1)The best sound quality of course would be, as mentioned earlier, is direct na ikabit sa power amp ang ipod. You might need a switching device to select between your in-dash car stereo or i-pod.
2) If your in-dash stereo has extra input jacks e.g. "cd/aux in", pwede rin dun ikabit. But sometimes may compatibility problems specially if the input terminal is built for cd changers.
3) If your car has a cassette player, you could also opt for a cassette modulator wherein a cassette shape device is plugged in to the player. Go for a Sony, but I got mine years back from orig discman car kits. May nakita pa akong modulator only, no power supply and mount para mas mura. Dont buy the NewStar brand modulator. My sister tried it. Walang kwenta ang tunog.
4) FM Modulators.... well, I have here in my desk right now a Belkin TuneCast2. Tinanggal ko because for me, kulang sa brilliance. Tried also my bayaws i-trip. Di pa rin ako happy. Didnt you notice that your cd's sound way better than fm tuning?
Yuung lang po. My two bits of opinion. Good luck and more power to all i-pod afficcionados. ITS SO FAR THE BEST THING THAT EVER HAPPENED TO PERSONAL AUDIO ENTERTAINMENT!