Interesting. Now I can see where it would be complicated to translate standard trackball movement.
If anyone ever catches wind of someone interested in working on a better solution for the shifters on the driving games instead of a TOGGLE, point them in my direction.
A few years ago, I made a spreadsheet of all the affected games and how MAME handles the input vs the true behavior (based on repair manuals). MAME Shifter Spreadsheet
The affected games are in green. A few more have had the toggle added since then; after MAMETesters reported the lack of a toggle as a bug.
I've learned just barely enough to remove the toggle and roll my own, but I can't foresee having the time to learn how to code something clean enough to be accepted and maintained.
Thoughts on how I think it would work from an end-user standpoint here, but it is riddled with people who don't get it and trolling. here