In order to enter a restriction race, your current car will have to meet specific criteria, so first check that you meet these requirements. Remember that the number at the top of the screen shows your car's overall rating and you can find your car's power rating on the upgrade screen.

However, not all cars will be able to qualify for all restriction race events, so sometimes you'll have to switch to a different car from your garage, or take a look at what's on offer at the car dealer.