Stop in for a cup of coffee

As long as its for off road use. Same with most race gas.
You can not fill your car's tank from the pump at a local airport.
Most airport sellers these days won't sell fuel except to those with a plane. I'm sure that is in part due to big mouthed people who post about how they get avgas for their cars from XYZ location.

I've seen listed few places have oxygenated race fuel for sale with road tax and not sure what various tracks do to comply.
Here they will sell it for road and race use but charge a tax to it.