Booked a Pontiac G6 at MCO...(lsted as class size C)...but used the following AWD and coupon that is 25% off plus one class upgrade:
AWD G417900
coupon UUWA006
I'm Avis preferred, so walked to lot to get car...my name wasnt' on the board..."Mr. Anvil is a small SUV OK for your upgrade?"
Certainly was! Brand new 4 wheel drive Kia Sportage with 9 miles on odometer. Very pleased indeed.

cheers!