When I first thought about detaling the engine bay all that came to me was blowing fuses, shorting circuits out and well the vehicle not starting. I have a friend who's a mechanic and takes care of my Volvo and the beater Jeep. So before I got near an engine bay to detail it I checked with my friend as to how to detail an engine bay. Basically my friend said that it all depends on the vehicle, the new vehicles are well covered with plastic panels that hardly any water gets through to the electrical components/sensative components. In some vehicles I've done I can't even see the air intake. But when it comes to doing some older vehicles (mid or late 90's) you have to be very carefull with the alternator, spark plugs and intake. So what I've done is I use a garbage bag and cover up the alternator, the spark plugs I cover with some old micro fiber towels or old rags and same with the air in take (I stuff a towe inside the air in take). So far I haven't had any problems with detailing the engine bay and I'd like to keep it that way but I'd like to hear how others are detailing the engine bays and if you got any pictures then please post them up, I'll check to see if I got any if I do I'll post them up.