My center bearing has gone bad with a thumping sound that sounds like it was in the rear. Looked at the car on the rack and all rear end arms were good! So with the car in gear and the engine running could see the drive shaft moving at the center bearing. Ordered the remanufactured shaft from wholesaleimportparts.com that comes with the front and rear guibo. It is the wrong one similar but has raised dowels on one side. Looking at the used guibo and could read the part # 2104110415, this shows up as the guibo for the C300 car.
I have sent a photo the vender, found some big price differences looking at different sites so shop around. Will have to wait until Monday to see what they will do for me.
Those guibos may have a different part number for the front and the rears.
Info on these on this forum is a bit confusing.
The SRT numbers are in this clip from an old thread.
The SRT uses two part numbers A 203 411 00 15 for the rear and A 210 411 02 15. Now here is where things get interesting! Mercedes dealers do have these, however the part casting number is not the part number on the boxes. Normally we see A170 for the slk32 and those are the part numbers on the bag, at least in my experience.
The units I picked up today are the a 000 411 02 00 and a 230 410 01 05
The part numbers on the parts show the model for which the part was first used or 000 XXX XX XX for parts designed to be used on many models.