door problems

i have an 03 Jetta 1.8T and my front passenger door sounds like a tin can when you close it. All the other doors are fine. i brought it to the dealership where i bought it and they said nothing was wrong. any ideas???? Normally this wouldnt bother me, but my friend who is all about the american made fords keeps sayin its my fault for buyin a cheap import not a ford.