I often play an awesome NASCAR racing simulator called "NASCAR Racing 2003 Season". It's a pretty realistic game. Sprint Cup series driver Denny Hamlin used the game to train for some races in 2006, including both of the events at Pocono Raceway (that he won). Dale Earnhardt, Jr. also plays the game.
But, anyway, even though the game was released in 2003, people make modifications to the data files so that all the drivers and teams are current. Others create new 3D models for the game so that the cars look exactly like they do today. Other people, like me, use Photoshop or GIMP to "paint" new cars to drive. Below are some pictures of my work. =)
They're not very good, but I'm slowly getting better. The ugly #24 was my first car, and the #9 is my newest.
Templates - Bullring, SimRacingDesign, me
Bases - SimRacingDesign, me
Numbers - SimracingDesign, me
Logos - Google, SimRacingDesign, me