[Skimmer]

You can create a variable for each player which saves the last ID of vehicle that has been created by him.

Код:

new LastVehicleID[MAX_PLAYERS];

Reset and delete it on join and on leave.

Код:

public OnPlayerConnect(playerid)
{
    LastVehicleID[playerid] = INVALID_VEHICLE_ID;
    return 1;
}

public OnPlayerDisconnect(playerid, reason)
{
    if(LastVehicleID[playerid] != INVALID_VEHICLE_ID) DestroyVehicle(LastVehicleID[playerid]);
    LastVehicleID[playerid] = INVALID_VEHICLE_ID;
    return 1;
}

And when you spawn a new vehicle just check whether the LastVehicleID is valid or not.

Код:

if(LastVehicleID[playerid] != INVALID_VEHICLE_ID) DestroyVehicle(LastVehicleID[playerid]);

Don't forget to assign the ID of the new vehicle after it's spawned.

Код:

LastVehicleID[playerid] = CreateVehicle(...);