Graphics and numbers on the cars. Nascar drivers are somewhat more courteous, Floridians will slam the door on you as you are trying to get in the lane. NASCAR drivers will back off as soon as the front fender of your car is even with their door, Floridians will gun it to block you out. Swapping paint happens with more regularity and vigor with no excuses on Florida's highways. In all fairness the worst offenders were cars from other states, NY, NJ, PA, and OH.