Just wasted 30 minutes this Sunday morning watching an infomercial for Zmax. Several endorsements (Shelby and Foyt to name a few) and the product seems to be successful.<br> <br> Has anyone added these three additives to their Mercedes? What's the result? Can a product really eat away all the carbon, seep into the metal and clean it out, and increase the life of your engine? The system includes one for engine, gas, and transmission.<br> <br> I have an '88 560SL with about 130,000 miles on it. It runs well, but could be better. What do you think?<br> <br> All responses appreciated!!