How can I turn on split screen in GRID 2?

These instructions are for GRID 2 Reloaded, but since that is only a few new circuits it should work as well.

From the Main Menu, select World Series Racing.

Select Events.

Select Splitscreen.

A dialog will appear prompting Player 2 to press the Start button. Player 2 must press a button on their input device to continue.

The Splitscreen menu will appear. Select Custom Event.

The game options screen will appear. From here, you can customize the game settings. When you are happy with your settings, select Done.

Select Go to Race.

The car selection screen will appear. Select a car.

The car selection screen will reappear. Player 2 must select a car.

The game will begin once Player 2 has selected a car.

Source.

I just tried this for the first time for my kids. You need to have done the intro race and the speedway to get the 'intro elements' done - then Splitscreen is an option in the events.