Can anyone tell me the absolute best place to ground the amp in the trunk of my 2003 coupe??

 

the closest bolt that goes straight to the body the less paint in between the better, check behind the carpet. as long as it touches bare metal youll be fine. I put a sub in my friends truck last week and grounded it to a bolt under the seat. in my old eclipse i had it grounded to the bolt on one of the tie down points.