[MrTinder]

Try this:

pawn Code:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if (strcmp("/car nrg", cmdtext, true, 10) == 0)
    {
        new Float:x, Float:y, Float:z, Float:a;
        GetPlayerFacingAngle(playerid, a);
        GetPlayerPos(playerid, x, y, z);
        new snrg = CreateVehicle(522, x, y, z, a+90, -1, -1, 0);
        return 1;
    }
    return 0;
}

public OnPlayerExitVehicle(playerid, vehicleid)
{
    if(vehicleid == snrg)
    {
        SetTimer("KillVehicle", 10000, false);
    }
    return 1;
}

forward KillVehicle(vehicleid);
public KillVehicle(vehicleid)
{
    DestroyVehicle(snrg);
}