The Car Lot is divided into 3 sections; Exotic, Muscle, and Imported Cars. As a beginner, your best choice is to get an Imported or Muscle car, the Exotic Cars are generally more expensive. As you collect more money in the game, you can upgrade to better cars. When you buy a new car, you don't lose your parts, they're just unequipped. You can go back and equip them once you buy the car. You will also notice that some of the cars statistics have been updated to fit the game better. You shouldn't rely on any of these statistics for real life purposes.