The guys on the Benz board say that they have rarely had a problem with the I/C. My sister is married to the General Sales MGR of a Benz dealer and he said the service dept has hardly ever had to replace one. The problem stems from, according to the Benz crowd, a cold engine placed immediately in gear and driven like a bandit.
The engine should be allowed a very short amount of time to warm up. Problem solved.
But the SRT-6, it's the best, fast, reliable, collectible car on the planet.