This is really great!
After 5 generations, the algorithm gets the wheel positioning/size right. In a few more, it figures how the lower middle portion of the car should be.
I'm in the 9th and I've already seen it go past 150.
Mine go further (230+) but I got a weird duncecap-like structure over the rear wheel that keeps cropping up, putting the center of gravity too far back and making them fall over backwards. Interestingly, instead of getting rid of the balance problem, my cars are evolving a wheely bar to prevent the backward flip at the expense of speed.
I wish the goal involved speed in combination with distance.
Update: stagnation after generation 10. I spun up another instance and it is amazing how different that one is evolving.
I'm experimenting with 'intelligent mutations' - when the cars look promising I reduce the mutation rate and when it looks stuck in a rut I increase it again.
I'm in the 9th and I've already seen it go past 150.