This is my method, always on a cold engine:

Spray on Megs degreaser, leave to soak for 10min then jet wash off.
Spray on Megs APC, leave to soak for 10min then jet wash off.
Towel dry any puddles & dry off any electrics.
Spray on AG Vinyl/rubber care.
Start car, get it up to normal operating temp. Going for a drive is quickest way.
Job done.