I have a 2008 Pontiac G6, if anyone has seen the backs of the seat they are a hard plastic and I believe they prevent alot of bass geting into the cabin of the vehicle. I was looking into porting through the rear deck lid where the 6x9 hole are with a chimney style port. Has anyone done this sort of thing. If so, how much of a difference did it make in spl. I hit 145.9 with 3k watts to Alpine type R's in the car but I want at leas 6-8 more DB. Any feed back would be nice from people who have seen or actually done it.