Go to any beach town in the summer and there are small planes towing banners, ads for events, bars, beer.
If one were able to rig some kind of quick change ads that looked good,
some money could be made driving up and down the main drag.
I would think a deal could be made with a beer company or some other young adult, beach or event related company.
The car would be painted much like the NASCAR race cars. Big logos, ad art all over. But no race numbers.
You come up with a schedule of summer events, one per week, perhaps more.
The deal would be, you will be on the road, around the event, driving, being seen by large crowds.
Sell the schedule to a company and you are up and running.