Mario told me about a new Lego based Hot Wheel toy. Then I found it later that day. So let's see how it does.
Sadly, the studs that are meant to keep the figure sitting down aren't very good. The figure is very loose and if you tried to do a loop the loop, it would easily fall out. It doesn't fit the foot studs either.
The stunt stud on the back of the car is a little better. There's a tighter fit and I could see the Lego staying on during a loop.
Much better are the hand holds on the front and back of the car. The Lego figures really grip onto them and there's no sensation that it might fall off.