They used to have them when I lived in New York. You had to take classes in order to use the lifts, tire machines, etc. I agree the insurance would have to be pretty high.

 

Waiver + Contract for rental of space that states any damage done to the facility/other users vehicles, equipment, bodily injury/ neighboring facilities due to, but not exclusively limited to: negligence, ignorance, straight up bone headed moves, etc........ Will be the SOLE responsibility of person found at fault.

It'll basically limit those who can work / will work on their vehicles there to just those who know what the heck they are doing. YES, Private business's can limit and refuse service to patrons they deem unacceptable to do business with. And some ***-hat that thinks you've discriminated against him isn't going to be fooling anyone with bad publicity. Heck, implement a nice little apprenticeship program for those that know somewhat of what they are trying to do, just charge a higher fee for the expertise that will be lent. Tuck that money away for a rainy day fund.