I also used it today for the first time and was quite impressed. I cleaned my wheels really quickly with just regular soap and a semi-stiff brush. I remembered after, that I had this spray that I got in earlier this week, I sprayed a lot on (too much almost I think, between 12-15 squirts). I let it sit while I did the other wheels, then went back and scrubbed it to work up an amazing amount of foam, that became very dirty, and stuck to the wheel really well. It pulled off a lot more dirt then I already had, and left the wheels with a nice shine.
I tried it on my dad's Durango too, and without anything other then the spray and some water, it made a huge difference. He had layers of brake dust on them from years of being built up and never really washed off. I only did it once really quickly before getting into the shower, and it got a lot of the built up stuff off, though I think I need either a couple more applications or something more aggresive to get off the really heavy stuff.
All in all it worked really well, and I think that for just 7.95 it wasn't too bad of a buy, I don't know if I would pay over 15 to buy it alone and get it shipped to my house.
It dripped on me a small amount too, but only after I had gotten around to the fourth wheel and sprayed a lot of sprays, no big deal, I flung it off my finger right onto the wheel anyways
