new lastVehicle[MAX_PLAYERS];

public OnPlayerStateChange(playerid, newstate, oldstate)
{
    if(newstate == PLAYER_STATE_DRIVER || newstate == PLAYER_STATE_PASSENGER) // If the player's state changes to a vehicle state we'll have to spec the vehicle.
    {
        lastVehicle[playerid] = GetPlayerVehicleID(playerid);
    }
    return 1;
}