How about Car Soccer? Hear me out..

There's that easter egg of a giant ball on top of a shack in the middle of the map in the vinewood hills. Someone with a sandking could get the ball into the back of the truck and take it to a decided upon location. Once there, fellow crew members will have placed boundaries of some sort (such as cars, trailers, etc.) in order to create a "soccer field" and keep the ball from rolling out of the boundaries. At each end of the field, there will be an empty space two vehicles wide which denote the goals (potentially wider depending on how difficult it is to score). More cars can be placed beyond the goals in order for the ball to not roll on forever.

From then we can decide on teams depending on who is playing. The amount of players involved will determine the field size. If 4 people are playing in teams of 2, the field can be made much smaller..if 16 people are playing with teams of 8 the field can be made much larger. There is also the potential to have more than 2 teams playing at once. Perhaps 4 teams of 4, 3 teams of 3, etc etc. In the situation in which there are more than two teams, we simply add a goal depending on the number of teams.

To make things as easy as possible, teams may need to be determined before the field and game are set up, so that each team has a "team color" of cars, in order to keep teammates in order. After each goal, the ball will be placed at midfield. Once at midfield, a 3..2..1 group countdown will tell you when the ball is live again. The only rules are that you remain on the playing field unless retrieving the ball, you remain in your vehicle at all times unless retrieving the ball, and are not allowed to use weapons (unless determined beforehand to be allowed, much like a GTA race). There will also need to be a certain limitation on eligible vehicles, or at least an agreement on what cars are allowed before the start of the game. Perhaps sticking to a certain class so that everybody is mostly equal. First team to a certain amount of goals wins.

Essentially we're combining a demolition-derby with soccer. What does everybody think? Setup may be time consuming the first time around, and it may be a game that takes a bit getting used to. But once we have 16 people within a boundary fighting for one ball and their goal, things could get epic.