Cleaning z3 engine compartment 1.9L

Ok so i just got my new(New to me :P 97) bmw and im wanting to clean inside the engine compartment. Im not really sure if i should just spray de greaser and hose it down. Of course cover some important parts or if there is another route i should take. any information is appreciated thanks

A word of caution, if it has a wire going to it don't spray anything on it.

I wash my engine compartment at the local carwash regularly.
They have an "engine wash" setting on the selector.
Low Pressure degreaser of some sort.
I close the hood after spraying it, then wash the rest of the car and finish off by rinsing the engine compartment with rinse setting.
Haven't had a problem yet.

Originally Posted by comsult

I wash my engine compartment at the local carwash regularly.
They have an "engine wash" setting on the selector.
Low Pressure degreaser of some sort.
I close the hood after spraying it, then wash the rest of the car and finish off by rinsing the engine compartment with rinse setting.
Haven't had a problem yet.

Yeah i figured but better safe then sorry. Some people at work told me leave the car running. should i? or just turn it off?

I turn mine off.