the passenger seat back tends to make a rattling noise sometimes when I go over bumps, I was wondering if there was any way to tighten it so it wouldn't have so much play and hopefully wouldn't rattle.

 

Not that im aware of.Try moving the seat into diffrent positions and see if it helps.

 

My 2001 has the same problem, although mine is almost constant and is beggining to be extremely irritating. There is no fix for this, as I have had it to the dealer 2 times with no solution. Sorry I can't be of more help.
Michael-Maryland