I extremely recommend getting a waterproof version. My son whom is 7, also seems to find every single puddle even when i tell him to stay out of the water.
The reason I tell him to stay out of the water is because I hate getting all the water out of the wheels, and all the care you need to give the car after its water session. Since he's 7, he'll just run off to the next fun thing to do and I'll be left cleaning the car.
All it takes is one puddle to ruin electronics if it's not properly waterproofed. A 7 year old will ruin it.
Seg