Thanks for your feedback!
I had the toolboxes set to be 5% spawnrate but it still ended up being too high, I think 2-3 would have worked better as you are totally right - when testing my web build I would often just crash into the rocks to get to the toolbox. I think initally I had it restore less health to each wheel and changed it at some point? It's a shame I ran out of time for balancing all the numbers... As for the wheel repair I mostly intended to be a last resort until you can get a toolbox, but once again, I think the numbers are slightly too low.. ':D