The only thing about backing into a spot at the grocery store is hoping you have enough clearance, when you come back to the car with your bags of groceries, to open the hatch!
Interesting... took and decided to post this photo without realizing the current topic. That is, the trunk, er, uh, cargo area, er, I mean, boot looks rather large with the seats folded down and the top divider removed. That's a 5 ft. X 7 ft. tarp, by the way. The size is perfect. (btw, the driver's seat looks black because I've got the factory cover on it).
No, you still have to scrub same as washing the car the traditional way; but the foam gun makes soaping up the car really easy (and it's also kinda fun). I'm pretty sure that this is what I have and it cost me $17 US.
Of course, my 3000 psi Karcher pressure washer cost me around $325 delivered several years ago.
You can buy the soap in a concentrate and dilute right within the container.
This was my first time using it. The concentrate, at least what I have, is relatively expensive (ChemicalGuys) and I haven't yet calculated how much each car wash costs with this thing.
As someone mentioned and depending on sun, temp, how fast the soap runs off the car after sprayed on, etc., when using a gas-powered pressure washer, you soap a little bit, turn off the pressure washer, scrub, fire up the pressure washer and do it again. I don't mind shutting the pressure washer on and off and really the process for the entire car is quick. How fast you can wash depends on the type of mitt/rag you use.
To rinse, I use a 40-degree, which that came with my pressure washer, at several feet away.