new CamperID[MAX_PLAYERS]; //globalna varijabla
// Pod OnGameModeInit, OnPlayerSpawn (prije provjere gdje se spawna)
CamperID[playerid] = 0;

// u cmd gethere, posto ona prebacuje interijer i to, da ako je admin u kamperu, djele zajednicku var.
// ovo mozes i u slicne cmd, znam da /prebaci to nema
CamperID[id] = CamperID[playerid]; //id je portani igrac

GepekVozila(vehicleid, &Float:x, &Float:y, &Float:z) {

    if (!GetVehicleModel(vehicleid) || vehicleid == INVALID_VEHICLE_ID)
        return (x = 0.0, y = 0.0, z = 0.0), 0;

    static
        Float:pos[7]
    ;
    GetVehicleModelInfo(GetVehicleModel(vehicleid), VEHICLE_MODEL_INFO_SIZE, pos[0], pos[1], pos[2]);
    GetVehiclePos(vehicleid, pos[3], pos[4], pos[5]);
    GetVehicleZAngle(vehicleid, pos[6]);

    x = pos[3] - (floatsqroot(pos[1] + pos[1]) * floatsin(-pos[6], degrees));
    y = pos[4] - (floatsqroot(pos[1] + pos[1]) * floatcos(-pos[6], degrees));
    z = pos[5];

    return 1;
}
bool:VoziloKamper(vehicleid) {
    if(GetVehicleModel(vehicleid) == 508) return true;
    else return false;
}
IgracKodKampera(playerid) {
    if(GetPlayerState(playerid) == PLAYER_STATE_ONFOOT) {
        for(new i; i < MAX_VEHICLES; i++) {
            if(!IsValidVehicle(i)) continue;
            new Float:vpos[3];
            GetVehiclePos(i, vpos[0], vpos[1], vpos[2]);
            if(VoziloKamper(i) && IsPlayerInRangeOfPoint(playerid, 5.0, vpos[0], vpos[1], vpos[2])) {
                return i;
            }
        }
    }
    return -1;
}

cmd:ulaz(playerid, params[])
{
    if(IgracKodKampera(playerid) != -1 && CamperID[playerid] <= 0) {
        CamperID[playerid] = IgracKodKampera(playerid);
        SetPlayerVirtualWorld(playerid, IgracKodKampera(playerid));
        SetPlayerPos(playerid, 0,0,0); //setplayerpos u interijer kampera
    }
    return 1;
}

cmd:izlaz(playerid, params[]) {
    if(CamperID[playerid] > 0 && IsValidVehicle(CamperID[playerid]) && VoziloKamper(CamperID[playerid])
       && IsPlayerInRangeOfPoint(playerid, 5.0, 0, 0, 10)) { // 0, 0, 10 tj koordinate interijera kampera, cisto dodatna provjera dal je kamper
        new Float:vpos[3];
        GepekVozila(CamperID[playerid], vpos[0], vpos[1], vpos[2]);
        SetPlayerPos(playerid, vpos[0], vpos[1], vpos[2]);
        SetPlayerVirtualWorld(playerid, GetVehicleVirtualWorld(CamperID[playerid]));
        SetPlayerInterior(playerid, 0);
        CamperID[playerid] = 0;
    }
    return 1;
}

//ONPLAYERSPAWN , gore sma ti napomenuo da ovo mora ici poslije resetovanja CamperID varijable
//Prilagodi sebi, OdabranSpawn i KamperKljuc su varijable.

if(Igrac[playerid][OdabranSpawn] == 7) {  //odabran spawn na kampera
    // ovo provjerava dal postoji njegovo vozilo, dal je model kampera i dal ima kljuc
    if(IsValidVehicle(owncamp[playerid]) && VoziloKamper(owncamp[playerid]) &&
       Igrac[playerid][KamperKljuc] > 0) {
        CamperID[playerid] = owncamp[playerid];
        SetPlayerVirtualWorld(playerid, owncamp[playerid]);
        SetPlayerPos(playerid, 0,0,0); //setplayerpos u interijer kampera
    }
    else { // vozilo nije model kampera ili igrac jednostavno nema kamper a taj mu je spawn
        SetPlayerPos(playerid, 0,0,0); //setplayerpos na pocetni spawn
        Igrac[playerid][OdabranSpawn] = 1; //promjeni 1 u kako ti vec ide za pocetni spawn
    }
}

Imaš i Igrac[playerid][KamperKljuc] != 0 // provjera ključa kampera, prilagodi sebi, ako je 0 ili nize navodno nema kamper.