If it's toy dino-speed, you'll be significantly taller after a longer shower, but not giant, and nothing will break. If I actually do the thing from the Spongebob opening on contact with water, I'd reconsider.

Ah shit, why didn't I think of that?

You would have to cover everything including your face, though, and that can get you funny looks in a different way.

I feel like those situations are already life-threatening to some degree, so I'll take my chances.

I'd assume growth over the course of just exiting a car wouldn't be too significant.