I got a HD foam lance from Ebay and its fab, cost me £45 but its worth it. I also find Magifoam (also available on Ebay) to be top class. Set the foam lance to full foam and cover the car with 2" of thick foam and leave it for 30 mins then simply power wash. Unless the car it caked with mud I find that there is no need to use a bucket and micro-mit.