How do I connect my iPod to the car?

Cassette adapters don't work well at all. If you have an aux input on your faceplate use a aux jack . 3.5 mm to 3.5 mm . If you dont have that then go with the FM transmitter as a secondary option. You set the transmitter to a certain FM radio station and connect it to your Ipod and set the same FM radio station on your in dash stereo. These are two of the best ways to play your Ipod through your car speakers.

I would start by cleaning it.. The digital/analog issue is completely 100% irrelevant in this case. Try cleaning it, and if that doesn't work, maybe have it checked out by a professional. Worst case scenario, you may need to replace the head unit with one that has an aux input or is ipod compatible. As long as nothing is defective (just dirty) your setup should work just fine. You can use an FM modulator, but it wouldn't really be any better than your adapter, and it might make more sense financially to just replace the head unit instead. It would cost a bit more, but the extra power and features of the replacement head unit would probably be worth the few extra dollars.