I ran into this tax scam in Michigan after buying my airplane there.
Actually the broker was there, the seller and buyer were both out of state.
Michigan has a 90-day period, during which we allowed Indiana to have our
money for fuel, hangar, rental car, etc. when we went to Michigan from our
main home in Alabama.

Also, more than 90 days a year in Michigan, you have to register the
airplane. Not a big deal, $30/yr. But registration triggers use tax if you
haven't already paid sales tax.

Stan