I work in the North Atlanta area. Being independent, we look at things a little differently than the Big Dealers. They tend to replace expensive parts without giving a thought to the lesser things.
I would start on the other end. I would look at the engine mounts, distributor caps and rotors and fuel pressures before throwing parts at it.
This is just my opinion, but I have MANY happy customers!
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS