Back in the days when I used to enter my truck in shows, I was constantly detailing it. Nowadays, well... I use the "I live on a dirt road and it rains a lot" excuse.
Anyway, you might want to check out Griot's Garage (
http://www.griotsgarage.com ), they're a mail order company in Tacoma that specializes in premium car care products.
I had a hard water problem when I lived in L. A. , and I also had no shade. My technique was to wash the truck and constantly spray the areas that I had already washed to keep the entire truck from drying. I would then drive a few blocks to a coin-op carwash and use their "spot-free rinse", which was soft water. After that, I'd drive to an abandoned gas station, park under the canopy, and dry the truck with a chamois.
If there's a coin-operated car wash near you that has a soft water rinse, you might want to try this.
Here's another detailing tip, it sounds kind of weird, but it works! Before I washed my truck, I would clean the windows and mirrors, and then coat them with Rain-X. I wouldn't wipe off the Rain-X, I'd just let the hazy film stay there on the glass. Then I would wash the truck, and go over the glass with the wash mitt as worked my way around the truck. After the soft rinse mentioned above, and a little wipe here and there with the chamois, the windows would be spot-free and crystal clear!
Andy