It's a really long way.
I spent most of my childhood playing with toy cars. I had hundreds of them and spent entire days pushing them around the house, the garden, the driveway. But my favorite game was letting them run down a steep hill. With a kerb or a brick for them to crash into at the bottom.
But I never rose to the heights of the filmmakers behind this awesome little short. It’s a demonstration of just how good Hot Wheels cars and track are; with a little push and a bit of gravity, the cars can run for hundreds of yards.
It was obviously filmed in several blocks, each varying in length quite widely. The swimming pool sequence is a bit suspect, but apart from that they were all clearly filmed for real. A few are even quite tense, waiting to see if the car will run out of momentum or not.
Most of all, this film shows what creative people can achieve when they have far too much time on their hands. Not only will it have taken ages to lay the track out, you can guarantee each sequence took at least half a dozen attempts to get right. I wouldn't be surprised if it took about a week to film in total.
Personally, the best I ever managed running my toy cars down a hill was about 100 yards. That seems a little unambitious now.