[park4bmx]

All u can do is on the callbacks "ExitVehicle" or "StateChange"
U can detect if the player left if so put them back in.
Edit

pawn Код:

public OnPlayerStateChange(playerid, newstate, oldstate)
{
    if(InEvent[playerid]==1 && newstate == PLAYER_STATE_ONFOOT && oldstate == PLAYER_STATE_DRIVER) // Replace ur variable for the event
    {
        new vehicleid = GetPlayerVehicleID(playerid);
        PutPlayerInVehicle(playerid,vehicleid);
    }
    return 1;
}