They are on sale all the time, you can get a small unit on sale for about $100 at CT, Home Depot, Rona, or any big box hardware store. You do not need the big one, all you need it a little extra pressure to was the soap off your car. Sometimes I do not even bother to hook it up and just use regular water pressure from the hose. As far as the dry/wet vac. it serves no useful purpose. If you have a puddle or something disgusting in your car that you need to vac ou, pay a few quarters at the gas station and vac it out there. I was talking to the guy that fixes the gas station vacs, he tell me that in the winter time people vac out the water, slush and snow into the vacs and he gets a big barrel of frozen mess. The usual crap he finds in the vac can are lots of womens underwear, pantyhose, combs, hair pins, pens loose change screws condoms gum wrappers and the other usual crap. and yes, lots of sanitary pads. ( covered in cigarette butts and ash )