I used it once so far and was pretty impressed. I just bought a brand new "Black" Prius and knowing how easily black will show scratches I thought one less step involving wiping and creating swirls would help. It did work well but as suggested, working in shade helps since it's still possible for water to dry on the car in the sun before the final rinse which is the part that prevents spotting. Hopefully this will cut down the amount of polishing I'll be doing in the future.

Break the stupid thing clean off and jam in a piece of thick wire. Long as it fits tight it's just as good. Might even be better than before. Mostly you need length not height. Longer it is the better reception. So if you use a long wire just curve it back. If it's real long then tether the end to your back bumper with a string.

As others have mentioned, a professional detailing. You might want to check with some of the smaller car lots in your area to see who they use. A full detailing includes the exterior and interior, so just the interior should be cheaper. If you want to do it yourself, ones of those "Little Green Clean Machines" works well but expect to invest several hours. If you don't have one, you can use a shop vac that can suck water. Buy some carpet cleaning solution (both general cleaning and spot cleaning), apply it with a squirt bottle, scrub it in, and suck it back up. Use the same solution/method on the upholstery. Carpeted floor liners can just be pulled out, cleaned, hosed off, and hung to dry. It's less of a problem this time of the year but make sure the carpet is fully dry before you close up the windows. In winter, I've seen car interiors get some really funky smells because the carpet wasn't fully dry.

As a teenager with my first car, a '74 Roadrunner, I was hand-washing that thing all the time. The neighbours swore I'd take the paint off of it. I like the notion of hand-washing and keep telling myself I'll do it, but I haven't yet. We'd run the car through the car wash......hubby liked the do-it-yourself spray ones. I did it recently and thought it was more pia than doing a good job, I was always panicking I'd run out of money before I was done. I put out a request for some car soap on Freecycle. A member who've I've traded stuff with in the past responded. He said he'd give me some, and also mentioned that he does car detailing. He'd wash my car and clean the inside for $20, or give me the shampoo, whichever I preferred. I said 'let's do both!' So I took it in, and he did the outside, the windows, rims, the dash, cleaned the floor mats, wiped down the leather seats, trim, and a light coat of wax. It looked great! So I still have my bottle of shampoo and I have permission for the landlords to do it. I wish there were some shade though. Once we have 'normal' summer temperatures, none of this 30C+ crap, I'll do it. Hopefully I find it as relaxing as I think.