You can buy more than one car of the same model (see below why).
The selection of cars available for sale at any given moment is different and changes every few hours, so you may not be able to get a specific car when you want it. They can be new or used (slightly cheaper, but may be damaged so they may have repair costs).
You're restricted to cars you own (but on the plus side the games starts you off with a rather large garage).The 'career' in DR2 is a bit of a gimmick.
