As already mentioned, by far the easiest way is to just look at the front brakes. Easy enough to do from a roll and you don't have to check VIN'S, crawl under the car or scrutinize the tires for sizing info. Kind of hard to miss 13" brakes and 4 piston calipers with "Supra" emblazened on them. If he was crazy enough to swap brakes, he just might have been crazy enough to go NA-T or swap to the GTE. Brakes are a dead giveaway and you don't even have to get out of your car.