Chiptuning

There is a second-hand car dealership here where you can see chiptuning written vertically on a pole with the c next to the h. Why is that? Because Czech ch is a digraph and has its own place in dictionaries, right after the h. Why after the h? I guess because they have similar sounds, but ch is more throaty. But interestingly, chiptuning is not a Czech word, so the h should be below the c, not next to it.