There are many messages about cleaning...try searching for these messages. Believe there is also info in the Tech Manual.
We have at least two esteemed members here who are (or were) in the car detailing business and have made many suggestions for engine and other cleaning.
A commercial degreaser, medium brush, and a strong arm are good for the heavy engine stuff...Simple Green will do a nice job on the less nasty grime. I have not used a hose on the engine as I'm fearful that even with the electric parts covered, harm can be done.
Years of dirt on a light color MBTex interior (Cognac, for example) can be removed with soap, water, and a brush. When this failed, undiluted Pine Sol (or other Public Toilet Cleaner) did the job with heavy brushing. Yes, the car smelled like a toilet for a few days but the covering was very clean.
Richard M, NYC
