Are those 110 or 220 motors? Did you wire them in with a switch or just a plug?
This is very similar to the idea I had for my garage. I planned to use two squirrel cage blowers in my attic, and draw air in from the turbines on top of the roof with A/C ducting, and have them blow into some large A/C return panels with electrostatic filters in the cieling of my garage toward the front.
One thing I wondered about was, I know that the 3M Filtrete filters would probably kill your CFM but would really bring in the cleanest air. Fiberglass filters are only really good for catching the big stuff. How well would electrostatic filters really work at higher air flow rates?
Could you use some sort of air filter sticky spray on the backside of the filter to catch dust or will this become airborne and get on the vehicle surface and cause fisheyes?
Sorry for all the questions, Im a noob lol.