1. You are wrong to call these people invaders as they are legal. Illegal immigration is much harder in Europe than in the US.
2. Idle rich buying high end cars helps the economy a bit. Lower income children aspiring to high end cars is even better if they seek to acquire them via work rather than taking from others. So your wealthy from the Middle East analogy is off base.
3. Point 2 is the issue of course, but then again do you really blame people for taking in a society that gives and makes earning difficult?
Aspiring to things is an important value to have. It is an important value for societal and economic progress. It is not the end all. It needs to be focused in a productive way by the market, but it is a start.
You made the point that when poor M.E. people show a penchant for such cars, this is provides an indicator they’ll later make positive contributions to British commerce:
Reversing the logic, does it mean that the absence of car-centric grad celebrations in rich, native-born areas in Britain indicates the young people there will grow up to be DRAINS on commerce, sucking up welfare...?