[/quote]
Well, they have all the right in the world to pump whatever grade
of fuel for their car, even coconut oil simply because it is their
cars and their money. 
I don't think it is appropriate for us to comment what grade petrol
they should go with. Surely you don't expect the rich to be in a
suit, wear rolexes and eat abalone at top notch restuarants all the
time.
It is their freedom.
For the same reason, you don't expect the 'not so rich' to be in
shorts and singlets all the time and drive only dae***, suzu**
cars.