I downloadied fotostation and I want some tips on how to put rims on the car and lowering it without messin up the background alignment. Any help would be appreciated. Thanks! Here is just a little window tint pic

http://i5.photobucket.com/albums/y188/MarkVIII93/Mark8010.jpg
http://i5.photobucket.com/albums/y188/MarkVIII93/Tint.jpg