DougE wrote:
I don't know your local building codes, but having propane on board probably presents more of a fire risk than garaging cars. If you're not doing an open structure like a carport, a separate building makes more sense.
I doubt the "propane" is much of an issue, I know people that heat, cook, heat-water, etc with propane in their homes.
Many areas do have some restrictions, like no propane appliances in basements (fire danger). But just propane in a home, probably not an issue, any more then the pipe coming in from the outside tank