The phrase "car roster" refers to a list or schedule of all the cars that belong to a particular group or organization, like a company or a sports team. Full definition
The game gives the option to «rent» any car for a race if your current car roster doesn't have one which meets the requirements of the race. (gearnuke.com)
No improvements to be seen; just an updated car roster. (ps3attitude.com)
While GT Sport may have the smallest car roster of this year's major simulators, that's not necessarily a bad thing depending on how you look at it. (xboxenthusiast.com)