An air compressor to blow out all the dust and sh*t, and then a nice coating of CD-2 Engine Detailer (Autozone, etc...) to give it the shiney wet look of a tire foam product. You can also use tire foam, which gives it a great detailed look - but it grimes up quicker and attracts more dirt/dust. I used to do this, but now use the CD-2 with much success.
Engine Bay
