Tried the Scrubbing Bubbles engine detail that I read about on a BMW forum. Sprayed down the engine and bay and let it work for 15 minutes. Then I rinsed the stuff off with my pressure washer. Used a leaf blower to dry everything. My engine was not filthy but it had been sometime since I last pressure washed it. Pretty impressive results and smells nice too. Afterwards I pressure washed the car and vaccuumed the interior.