Sorry I don’t post here very much anymore, but I do look at stuff here from time to time. This X66 & GM top cleaner discussion really caught my eye. This stuff is something that I have used on different cars exactly 6 times. Why do I know exactly how many times? Because it workd really good the first 5 and on number 6 the engine seized up some pistons while I was blowing it out. It was an old girlfriends old chevy Corsica. She got rid of the car and I got rid of her. Ha ha. 2 problems solved. Who wants a girl that drives a chevy anyways, right? I know that we are in a Mercedes community here, but an engine is an engine. No offense, but it sounds like at least 2 people here know their ass from a hole in a block. Lighten up and chill out people!