I have the pac audio adapter for my ipod already installed. my opinion is the same song from the ipod sounds better than when the same some is on a cd. dont know why, dont really care as long as it doesn't distort. I had a smile on my face the entire day after i installed it. FM modulators are no comparison irrelevant of any new technology etc. I just bought the av electronics unit yesterday and im positive the sound quality with the pac audio will prove better by far than the fm modulator. Given the price of the pac audio being relatively inexpensive i dont see why any other option is even an option. The instructions of install are on this site are great, just take your time, be careful and i promise it'll go quicker than you thought it would. IF YOU DO INSTALL THE PAC AUDIO, WHEN YOU REMOVE THE DASH CENTERPIECE MAKE SURE YOU LAY SOME TOWELS DOWN ON THE FINISHED DOUBLE DIN PANELS. YOU WILL GUARANTEED SCRATCH SOMETHING OTHERWISE. hope this all helps. ill take pics of the av electronics install.

 

I used the FM modulator with my AV box for awhile, then I installed the PAC.
Using the FM modulator the sound was not terrible but it is better with PAC. With the FM, the sound was somewhat muted and dull compared to the PAC direct inputs.
Though installing the PAC was time consuming, I'm glad I did it. Now besides better sound from my DVDs, I can run my IPOD in the car. Like SK said though, be careful with the silver finish surrounding the center console, it scratches easily. I took painters blue masking tape and taped off just about everything on the console before I started taking it apart. It saved the console from scratches and was easy to remove when done.
Good luck.

 

When I first started using the fm modulator I thought it was ok. After installing the PAC I realized the fm modulator sucked.