How Do You Activate 8 Ball Car Bombs?

I have driven a car into 8-balls garage and it has a bomb in it now, but I have no idea how to explode it. What button do you need to press?

If you have been to 8 ball and your car has been fitted with a car bomb, you can arm the bomb by pressing O (circle) while inside the car.

Once the bomb has been armed you can get out and run away from the car and it will detonate the bomb.