Roll of cling film for the electrical connections and air intakes
AG Engine and Machine Cleaner
Alloy wheel brush, old toothbrushes, Envy detailing brushes
Hose with no attachment
Wrap the connectors, and rinse.
Spray cleaner generously, agitate with all sorts of brushes
Rinse
Repeat as needed
Dry
Make sure you start with a cold engine!
That's a starter before then replacing bits and bobs for shiny / coloured / carbon stuff. If you just want to dress whats there, then AG Vinyl and Rubber Care bring the plastics up a treat