I use a citrus cleaner, virosol its called got 25ltrs of it the other day so should last a while.

I use it on the engine, wheels, arches, cleaning plastics it great stuff imo been using it for years.
I've used AG engine and machine cleaner in the past, spray it on the engine/engine bay and work it with a rad brush/sponge then rinse off, but I always found that when drying it left white marks everywhere, a quick going over with a mf and it soon came off though, ready for some goulash to treat the plastics/rubber.