RE the 3M cleaning and tune up. I am doing it every 18 mos or so. No noticeable differences. But, lots of crap comes out of the tail pipes. With DI engines, it just seems like a good idea for 30 bucks. Plus its kind of fun to do. There is a great video on YouTube using the system on an SHO. It is 3 parts. One part goes in gas tank. Then there is a throttle body cleaner, then the main cleaner which gets inserted with a tube into the TB area. The video is mucher clearer than I am. Lol