I wouldn't exactly recommend cleaning a filthy engine bay with CD-2.
I would recommend cleaning it with Simple Green Automotive. works like a charm.
THEN CD-2 it.
CD2 seems to work more like a show car shine/polish instead of a degreaser.
For heavy brake dust, we use plain old Simple Green. we spray it on and rinse with the high pressure nozzle on the hose right before a full car wash. It doesn't always get it all off, so sometimes scrubbing with a sponge helps.
since we wash our rims so frequently, the brake dust really isn't too caked on, so by the time we come to the end of the car wash, we just wash with the remaining bucket of suds and the rest of the filth comes right off.
