Selling at the meet without having a table is prohibited.
Not sure about the whole parking lot deal, but it takes away from the dealers who actually pay for tables to be there, so I don't think it will be looked favourably upon.
We can't police the parking lots, so I have no say in what happens there.
Should dealers complain, then you'll have to leave the property to complete your deals. This event isn't being run so someone can "cash in" outside of the event.
I originally had no problems with things happening in the parking lot. But now that I see Stealth's post, I DO have a problem with people circumventing the Joe Meet and taking potential money away from dealers.