First I'm assuming that vehicles will be in the game AND we will be able to fight with them.
Where there are people, there is entertainment. Gambling and animal pit fighting are fun, but they only take you so far. Vehicles death matches are the way to go for entertaining the mass. Take the Roman Empire, they had arenas full of gladiators fighting often to the death for entertainment. They recreated battles involving chariots, foot soldiers, cavalry, archery, etc... And the people loved it!! Why? Because it was fun, and they could bet money on them.
What I'm offering is a similar concept. What I imagine is, PVP matches of 2 or 3 teams facing-off in a maximum of 3 cars each with a max of 4 passagers per car. Each car would have one driver and 3 possible passengers at the start of the game. As the game starts passengers can leave the car at any moment and fight on foot. (Why the hell do you have cars then?) (Stick with me)
Whether you're a driver, a passenger or on foot you have pros and cons.
The driver: he drives the car and shoots
Weapons: One handed and the CAR (For people on foot)
Pros: Protected by the car, you have a car for a weapon.
Cons: One handed weapons only
Passenger: Follows the driver and shoots
Weapons: One handed, two handed
Pros: Protected by the car and can use two handed weapons
Cons: You don't drive, Can't use Big Guns
On foot: Normal foot soldier
Weapons: Any
Pros: Can use Big Guns
Cons: Vulnerable to raming and not car protected
Car: Protect the passengers until it blows up.
Not only there could be death matches, but also King of the hills, forts, death races, flag grabbing, etc...
Alliances, guilds, enemies, teams, friends, strangers could fights each other until real life do them part. All with their own custom cars.
As for the rewarding system. The best team wins and gets the most reward. Whether its money, fame, equipment or all of the above, I leave to gamesas.
Hope you liked the idea. PLZ comment, we can only improve on the concept. "War. War never changes."
- Ron Perlman