Got a 2005 NA coupe, new guibo's and Koni's I have a bump in the back on bumpy roads. On the lift everything looks good. New rubber hangers on the muffler. Trunk empty took rear bumper cover off this weekend, no lose parts.
Does not change with deceleration or acceleration, possibly the rear hatch?
Any ideas?
Dan
🤔 Maybe, gently press on the hatch and see if it moves, if you get a bumping sound you found your problem if not move on and keep looking. I have a roadster and it definitely has adjustable stops on the trunk lid but I'm not sure about the coupe. One of the coupe owners will chime in and help you out with that.