I have never had any problems with pressure washing, I use the 25 cent car wash which I believe is around 1200 lbs psi. Obviously you have to use some common sense and keep the tip back away from some areas. I wouldn't put it up close on anything electrical like an alternator. Like I said in my earlier post I've had good luck with this method. The only side effect I ever experienced was a set of soggy plugs in an Acura that apparently leaked past the boots causing some sputtering, DOHC set up. A quick blast with some air cured that.
spl_dodge, I like the No-Touch tire cleaner and dressing. Not as wet looking as some products and doesn't seem to attract dirt. It also make the tires easier to clean the next time. I have never thought to use it anywhere else. Thanks for the tip.