IMO most people (including myself!) are playing the game wrong. You're clearly not intended to own all of the cars, but focus on a few you like. It's almost impossible to buy both the F1 and the 917K at the same time if you do less than braindead grinding.
Or, you can buy credits with money, but the MTX are so expensive that they're worthless, especially when 1 hour of grinding gives me similar income.
That being said, delaying the F40 just before a price revision was a kick in the nuts. Who approved this decision?
Also the McLaren F1 is one of the cars in the game with the coolest upgrades... I'm scared of widebodying it, but man, does it look good with all the racing bits. I feel for people who can't buy one in the game.
Easily one of my favorite supercars when it comes to upgrades, next to the... F40.