You can share your B-spec driver. There is an option to do this in the driver list I think. Go to the driver list screen and choose a driver. Then, find the world icon near the bottom of the screen (over to the left?). It's the same as sharing a car with your friends.
I have not confirmed this feature actually works. But, what I've written is fairly accurate on how to find the setting.
Edit: Apparently it's not yet functional.