I installed my Sunsetter 12' this summer and love it. I too had the 101 questions on how to install on vinyl siding, 2 story home, how do I find the studs (impossible with a stud finder when homes are wrapped with OSB or ply).
Using the nylon spacers was brilliant, saves the look of the exterior and works great! Very strong,that was my main concern spacing the back of the bracket "off" the flush exterior. But that is not an issue. I did however buy one extra bracket and installed in the middle for peace of mind with wind/weight, but prob not nessesary. Alls well. can't wait until next summer to use again (I'm in Western Canada).
Follow the Sunsetter Dealers instructions regarding the install with Nylon spacers. I did however use some knowledgeable help from friends (ex framer) to ensure i located the 2nd Band Joist, finding those studs is near impossible, the band joist is thick and strong, and ideal hight. I did buy smaller lag bolts as the band joist is like 1/2 to 3/4" thick only if I recall, but it is very strong ply regardless. Awning is in solid.