>I'm sure I could tell them to kick rocks, and they would have to write up a subpoena but there's no reason to do that

Would they have the right to subpoena you though? Over mere suspicion that they think a vehicle at some point drove a certain direction?

Sure if it was a case involving me personally I'd probably be cooperative, but I don't fancy the idea of just letting LEOs just waltz into my property to "just to take a look"