I could entertain you with a funny story about how/why I bought my pressure washer, but will save that for some other time.
I went for a honda powered unit with 2,600 PSI. It is about middle of the road in terms of power, but works well around the house and shop.
At the same time my buddy bought a 3,500 PSI unit. He decided to squirt off his 89 vette with the washer. Yep, you guessed it, it was peeling the clear coat right off the front bumper and he did not even notice until he took about a solid square foot of clear paint off. His unit would dig holes in the driveway if held in one place too long. He drew blood out of his calf when he was careless with it one time as well.
I have run mine over my foot (pressure blasting with sandles) and just made my skin raw and red.
Mine on the other hand is fairly mild. I would not hesitate to wash a car off with it, but would not consider getting the nozzle closer than two feet to the surface.
I use it for household things just like Tom, and I use it to power wash engine bays, suspension parts, greasy engine parts, things I drag home with my truck, and mostly the floor in the shop.
I recently used it to power wash the belly of my buddies 71 vette while it was rolled over on its side, and then power washed the privacy fence to make it look new again. Then I got carried away and blasted my dually engine bay and frame. Ended up blasting the undercoating and paint off the front frame rails and had to wait until it dried so I could apply some fresh paint!
Got mine at Lowes back in 97.