[Chaprnks]

Possible temporary fix, if you don't already use. Also would fix the bug of putting a player in any seat that someone else is already in.

pawn Code:

// Has to go before all the PutPlayerInVehicle's, or you can manually rename all them to whatever.
public SafePutPlayerInVehicle(playerid, vehicleid, seatid)
{
    foreach(Player, i)
    {
        if(GetPlayerVehicleID(i) == vehicleid && GetPlayerVehicleSeat(i) == seatid)
        {
            return 0;
        }
    }
    PutPlayerInVehicle(playerid, vehicleid, seatid);
    return 1;
}

#define PutPlayerInVehicle SafePutPlayerInVehicle