I had one for three years a little while back, generally it was pretty solid. Listen out for clicking from the ventilation system on startup, it’s a stepper motor that fails on all CLK’s. Mine did it then stopped (I guess the motor died) so I left it, fixing it properly is a dash out job. Mine eventually had an expensive ECU problem, but I think that’s a random failure rather than something AMG specific. The drivers side heated seat failed, I was told it was going to be expensive to mend, so (you guessed it) I didn’t bother. Generally it was one of the better car’s I’ve owned.