Ummmmm, I clean it. Dee dee dee. LOL Nah Just playin. When I bought the car about 6 months ago, it was immaculate. I bought it from a Honda dealership, so they detailed it, I'm sure. I work as an auto detailer, so I know the tricks of the trade and I've cleaned it twice since I bought it. (So like every 3 months) Really it comes down to cleaning it and then dressing all the plastics and rubber with Armorall or similar dressing. (Not Black Magic, that shit is too thick.) I posted good engine bay cleaning instructions on page 1 of this thread, I think. Here they are:

I don't wrap anything. I detail cars, and we never cover anything unless you have a intake (then you just put a folded up towel over the filter) You spray the whole bay down with Simple Green ( on my car, I use Simple Green, but at work we have a "professional strength engine degreaser" I prefer Simple Green.) scrub it a little at what you can get to, start the engine, then blast it with a pressure washer. You just try to move it quickly over the alternator, distributor and fuse box, so the water doesn't get forced into these areas from the pressure. The reason you start the engine is because if the motor dies, or if you get a CEL or some other wierd electrical problem, you will know it right away. Also the heat from the running motor will help dry everything if you shut the hood once you are done rinsing. Then I usually follow up once everything is dry with some dressing (armor-all or similar product) and mist all the hoses and plastic/rubber in the engine bay. Then take a towel and rub it in so there is no streaks or spots. It makes everything look brand-fucking-new! Oh and don't forget to clean the underside of your hood!