RE: wash
Once upon a time, a long time ago - I worked for various manufacturers of high pressure cleaning equipment, eventually risiing to national sales manager for two, and working in product development for a third, so I'll chime in here.
If the CARC surface is in good shape, you'll have no problem with the washer itself. If the paint has cracked or chipped, or has underlying rust, a high pressure washer operating at four or more gallons per minute and 2000 PSI or more pressure can removed the damaged paint.
Most coin-op car washes are typically in the 4 gallon per minute 800-1400 PSI range. "Touchless" car washes use a great deal more volume of water, often at lower pressure.
A very hash alkaline cleaning chemical - such as an industrial degreaser - will remove oxidation from the paint. This is apparent particularly if you have done an uneven wash job, especially on the black - where there will be streaks. Some of the black will be "blacker" than the rest - the truly clean being jet black, and the oxidized having a bit of a gray tint to it. This doesn't effect the servicability of the paint, only the appearance. Certain acids can produce the same effect, but this aren't available to non-commercial users.
HTH,
David