Stop Slamming The Door!!!

[drbgm]

Every time, no matter how soft or how hard someone closes the front passenger door, it sounds hollow. Not a rattle, but a hollow tinny sound. I've tapped on the outside of all the doors when they are closed and all but the front passenger door have a nice dampened tone. The f p door sounds empty. It is a 2002 that I bought February 2, original warranty has just run out so the dealer wants $$$ to go exploring. Have any of you heard of quality control issues like forgetting sound proofing? Just a thought. Still very annoying. Suggestions please.