I worked for basically three different shops over my career and all three started out as guys working out of their garages. The way the money is accumulated is by NOT spending it outside the business. They were all able to FIRST generate profits from their own labor, then getting guys to work for them. THEN they were wise enough to always plow those profits back into expanding the business through boom and bust economies without bankruptcy. Even in the instances where the 2nd and 3rd generation came in those principles stayed in effect. Our tax policy is very favorable to re-investing the profits because ultimately you can pay yourself a modest salary that covers your essential needs and let the business pay for "work related expenses" like luxury cars, luxury RV motor homes, business meals and travel with clients, country club and yacht club memberships, suites and season tickets to professional and college sports teams...............you know, BUSINESS EXPENSES.Absolutely... You gotta have somewhat of a bankroll to get started... But that's pretty true in any business.
The other dilemma is you can't hire the crew until you have the work, and you can't get the work until you have the crew...
I think the BMW and Mercedes comes way later...
You will need good accountants and lawyers to make sure everything is legit. Lots of fools just never figure out how to live like this LEGALLY. In fact, the norm is they blow all their profits before they ever get the point where they could put the down payment on the Mercedes.