More than 80,000 prospects will be sent a personalised copy of the game. It is also possible to download.
Users can customise a CLC 350 sport, the range’s flagship model, before aiming to set the fastest time.
The top time recorded over the next three months will be entered into a prize draw, with the winner receiving a real driving experience at Mercedes-Benz World.
Ian Dutfield, Mercedes-Benz marketing director said: "The CLC is attracting a new kind of customer, so we wanted to promote the range in a new and exciting way.
"CLC drivers are often choosing their first executive car, and are searching online for information – CLCdreamtestdrive.com adds an enjoyable element to that process."
Online racers will also be able to book a real world test drive or see finance rates and residual values.