Thanks guys for the info. I am leaning towards looking into the "Deckster". No matter what spray method used, the challenge seems to be trapping or blocking unwanted overspray.
I have a horror story about overspray. Last year, about my eighth deck, I was trying to figure out a way to stain cedar shingles on the "turret" of a gazebo. It was a steep, high roof that couldn't be laddered. I was having good luck using a pump up sprayer with my prior jobs, so that seemed to be my best option. Standing on My 10' ladder, I carefully sprayed the Ready Seal onto the shingles. Everything appeared to be fine. The shingles were looking great and overspray seemed to be minimal.
Or so I thought.
Little did I know, that the homeowner had moved his brand new Chevy Silverado from the garage out to his driveway. I was in the backyard and did not realize this...but I also didn't think I had an overspray problem. The homeowner brought to my attention a few hours later, that there was overspray on his truck. An understatement! Bumper to bumper was covered with needle point size drops of stain. I just about had a heart attack!!! Quickly We started waxing the truck, and it worked to remove the stain. The truck had to be hand waxed twice but it removed everything. I was lucky. The owner and his wife helped with the waxing. They were very cool about the whole thing.
The job ended up being one of my best jobs. I tried to take $200 off the bill for the inconvenience. The owner said no. I finally managed to get him to agree to at least take off $100. I said at least use it to take your wife out to dinner for the trouble.
I have hardly sprayed since then...I am a little gunshy. So many people on this bulletin board are doing it with success. I am ready to give it a try again. I will be very aware of potential overspray. By the way, when I was spraying the shingles I checked for overspray all around the area I was working. Somehow the wind carried it over the house and onto the truck.
If anyone does get oil based stain on a vehicle, try using car wax ASAP. Moral of the story: Beware overspray.