Exclusive Taste Achievement
Own the five most expensive cars in the game (not including DLC).
You pretty much have to accumulate 38 million credits to unlock this achievement, and then waste it all on stupid cars that you probably don't care about. The easy thing about this is that you do actually get one of the cars, the 330 P4 at Driver Level 30, so that is 9 mil you can keep in your pocket. If you want to keep the other 29 mil in your pocket just buy 12 car tokens which will cost you 800msp for 13 tokens - don't do that though, you only encourage Microsoft to keep on doing such underhand tactics. Just waste in-game credits... after all, it's better to spend fake money than real money.
The 5 cars in the list for the achievement are as follows:
1964 Ferrari 250 GTO - 10 million credits
1967 Ferrari 330 P4 - 9 million credits
1957 Ferrari 250 Testa Rosa - 8 million credits
1958 Aston Martin DBR1 - 6 million credits
1965 Shelby Cobra Daytona - 5 million credits