+1, there is a Lambo owner in so.cal who has a couple of lambo's but drives a Honda Civic "NGV" Natrual gas. He said the # of miles he puts on that civic is just about more what you mentioned in the post but he says saves a lot on $ on service and fuel.
I don't want to discourage used high end Luxury cars, there are some good buys out there but in cali, catalytic converters do fail and cost an insane amount of $$$$$$ in some cases they cost more then the car itself as for the Audi story, been there done that bought one for parts and it was that just a parts car to fix another one.