Hello
I recently purchased an 03 CLK55
I noticed when i hit gas fast while at a crawl and let off I get a big bang from rear of car. As well in traffic when I gun it in order to make a pass and let off gas fast the bank comes out again and I looked in drivers mirror and can actually see the car jolt up
PLEASE HELP!

Perhaps you are releasing the gas pedal when the transmission wants to engage the next gear and by you now letting go of the accelerator pedal, this is the result of that. Maybe try doing a flat out through all the gears and see if this still persist. I would thereafter do a tranny oil and filter service if you already haven't done one. Next point would be to inspect the flex disc on the propeller shaft front (between prop and gearbox) and rear (between prop and differential housing) ones.

I'd suggest inspecting the rear and front guibos - the flex disks at each end of the drive shaft, and the attachment points to the rear subframe. I would treat the car gently until you find out what's happening.

I agree with the driveline inspection.

Center carrier bearing for drive shaft, trans mount, rear control arms, exhaust mounts, Shock bushings, third member hardware.

Easy does it until you find it, I have read about the flex disk coming apart and ripping the trans tunnel out of the car.

cheers, Gator