I did my last one with Auto Glym Engine and Machine cleaner. Sprayed a lot on and agitated it where it was needed with a paintbrush, then gave it a good rinse off with water (no pressure, just a plastic bottle).
After that I sprayed it all over with Auto Glym Vinyl & Rubber care, and then just left it all to dry. It came up REALLY well, and the V&R care makes all the surfaces look really good, especially the plastics. Whole process never took long either.
I didn't actually cover anything up before cleaning, just went for it, but in hindsight I would cover a bit more up next time.
Cheers