Transport Insurance here as well ($105 month for bobtail on a 2006 Sprinter) - and I do the same as the Rev. - pay with a Chase MC card that offers 3% cash back, I also use it for all my fuel purchases.
I've gotten two $100 cash back checks since last fall when I got it, and I should have $200 in current rewards when my statement cycles next in a few days (if you wait until you have $200 before you redeem they actually pay you $250 ..... bonus Garth !!!! .... Sweet !)