My 2004 is doing the same thing as we as the headlight lenses have gotten hazy. I used some Meguiars Plastic Cleaner and Polish with a foam pad in an orbital buffer and cleaned up the headlights. I have not done anything with the grille yet.

 

I have the same problem with the plastic fading with on my 05 PAC especially the front grill. I use BLACK AGAIN to restore the faded plastic. It's been a month now since I applied and its still look good considering the crappy weather that were having. BLACK AGAIN has been used by professional detailers. I bought mine online for $6.00 a bottle.

 

I second the vote for the Black Again product. Amazing stuff. Removed the scratches on the plastic dash components as well.

I've used it on the house vinyl windows and it even restored the colors to our faded brown aluminum storm doors.

 

TRY Armour All. Not sure if its available in U.S. My wife used it on our 04 and came up like new. 3 months later its starting to fade again but its a quick wipe with armour all and new again.