2008 audio system

have a 2008 quest base model; when using the cd and mp3 inputs, the sound is great, but when using fm it sounds like its in a tin can on every station, any suggestions to help with the sound quality? been in another 2008 that has the same sound quality issue so don't think that it is my problem alone, sound like something is disconnected or would i need an amp installed?

2004 Audio System
Great question regarding the sound. I have a 2004 quest and am having the same issue. I check the manual and it said the antenna is the lines on the window. The reception is awful. Any help would be greatly appreciated.
audio system
Still have not been able to find out why the audio has poor quality. I dont think its an antenna issue though since it has no problem picking up radio stations. I still think that the system needs an amp or something, dealer has no recommendations either and i have asked other audiophiles about it and they said to look at another van, but the others i have seen sound the same way too. Just seems strange since the MP3 plug in and CD player have great sound quality.
2008 SE with Bose System
I checked the FM station in my van today and they sound fine, so I guess this maybe an AMP issue and you may want to see if it is possible to add an aftermarket Ampifer into the van.
Good luck