I've never towed anything either. Did it for the bikes. I've still got the hitch rack on the Outback until the youngest comes at Christmas (assuming Colorado isn't still a banned state) to drive it back to Denver. So next season, the bikes need a transporter and my spouse isn't having any of that on her car.
Yeah, our roads are rough but maybe I've just been lucky. I think I've only gotten two flats in my life. One was at the pediatric dentist and not even me, but I was working a couple miles away and my wife called for a rescue ('91 Ford Aerostar). The other must have been in '73 on route 18 in East Brunswick because it was in my '68 Mustang which I sold in '74 to buy my 260Z.
I think they are supposed to give you the sales tax form. I attached mine. Basically I think it certifies to the state that you are exempt.