instead of the armor all, I used to use silicone spray lube/protectant. spray it on the hoses and wipe it off after about 5 min so there's no greasy buildup.
when the engine gets dirty, I use gunk engine brite and an old toothbrush to scrub down anything messy- power steering reservoir and around the oil cap, stuff like that... simple green works just as well.
the one major issue is DO NOT GET THESE CLEANERS ON YOUR EXTERIOR PAINT! If you do, re-wax that area as any type of degreaser will strip the wax off and dull your paint.
http://mattblehm.com/pics/old_max/car/good_pics/3.jpg
http://mattblehm.com/pics/old_max/car/old/engine1.jpg
that was my old one that I totalled 4 yrs ago.. now I could care less what it looks like as long as it's fun to drive.. I don't even have pics of the engine bay unless I was doing a writeup for installing a mod or something.