This isn't really a big concern for me, but is my Civic the only one thar rumbles the passenger seat like crazy when the car is stopped. I'm sure there is a term for it but the seat rumbles a lot. It actually surprised me the first time it happened, I thought it was coming from the car itself. So is this normal? Or is there something wrong with the car?

thanks

 

lol
4 bolts hold the seat - 2 in front and 2 in back.
check to see that they are tight