After 2 years of racing this is what I have found to work best for me. I have not tried everything, but very happy with my current procedures.
Between races full cleaning:
Take out fuel tank, engine and radio tray. spray chassis with simple green and let sit a few minutes to penetrate the dirt. Brush only where needed for those supper dirty spots. I then hose off the entire car with as much pressure as possible. Quickly dry it with an air compressor and spray WD-40 into all bearings. Blow off excess WD-40 and spray with Kalgard Prep and shine. Brush in/off prep and shine.
Plug up engine and spray with simple green and brush off. dry with air compressor.
Light spray of Kalgard degreaser on the radio tray and clean with toothbrush. wipe off with rag and then blow off with air compressor.
Fuel tank gets plugged up and washed in the sink with a brush and dish soap. Dry with air compressor.
Put it all back together and it looks brand new!
At the track between rounds I will spray my entire car (not air filter) with Kalgard degreaser and just brush and then blow off with Air compressor. The prep and shine keeps allot of the dirt from sticking and the degreaser gets the rest of it. Car looks right out of the box after every round and the degreaser has a mild lube in it to keep everything free and lubed..
Extensive testing has proved to me that these methods just work best for me.