// In cima
new
    Veicolo[MAX_PLAYERS],
    bool:Uscito[MAX_PLAYERS];

// Sotto OnPlayerConnect
Veicolo[playerid] = -1;
Uscito[playerid] = true;

// Sotto OnPlayerExitVehicle
Veicolo[playerid] = -1;
Uscito[playerid] = true;

// Sotto OnPlayerStateChange
if(newstate == PLAYER_STATE_DRIVER)
{
    Veicolo[playerid] = GetPlayerVehicleID(playerid);
    Uscito[playerid] = false;
}
else if(oldstate == PLAYER_STATE_DRIVER && newstate == PLAYER_STATE_ONFOOT && Uscito[playerid] == false) PutPlayerInVehicle(playerid, Veicolo[playerid], 0);