"Hello, Grandma [name redacted]?" and he proceeded to tell her that he and his friends drove over to Toronto last night and that they were speeding and got pulled over and they had a little pot in the car and... he was really sorry, but he needed money to get out of jail.
I suppose this is a good scam, and I know friends' grandparents who have fallen for it unfortunately, but it doesn't really work when your only grandson is a preschooler.
I suggested that she should have said, after listening to his whole story, "Well, sweetheart, you have to expect to be arrested. It IS illegal to drive when you're four years old..."
Especially when it is a 2000 mile overnight trip with drugs in the car, I would imagine.