My partner and I started out "mobile" working for dealerships - doing installs & accessories. After about a year on the road working our normal jobs and taking care of dealerships "on the side" we could finally afford a few month payments on our current building.
It's been over 5 years & we have moved from doing lift kits only, to now having a paint booth ( for insurance work ), alignment machine, nice equipment, etc.
I think you could start out in your garage "weekends" & put that extra money aside until you can get yourself into a building and float the payments for about 6 months - until you get booked up!
Good luck!! {toast}
Stay South of Atlanta LOL!