Great! I've always wondered why they hate caliper so much that it is that rare. Consider:
- introduced in chapter 15, all other violets are available sooner
- available in one race only, not even in chapter 19, where there are 4 races with violet parts?!
- and the only violet part, where the event offers a common material as well
Second most hated (rare) material is thrust sleeve, the only common material available only once in first 9 chapters, and that is in 2 fuel race (all others can be found at least once in 1 fuel races, as well as many uncommon materials)
What would make an excellent addition to the value of the list would be WHERE to find them. When in need of a specific material, I usually make a list like:
tread - 2nr, 9rh, 11nr, 14tt
relay - 5nr, 8rh, 13rh, 15h
--- nr - nitro rush, rh - rush hour, tt - time trial, h - hunter, b - blockade, a - airborne
(so that when going to the underground to spend fuel, I know where to stop by, and not having to go to the garage, find a car that has a free slot for that specific material (it may be the case that it is not the car I am actually upgrading, I may be waiting for a kit to upgrade first, but still know I'll be needing battery, hoses and for example pressure plates) and then to launch material finder with this information. I greatly miss material finder on the material list in the storage)