Hydraulic master cylinder - Firewall flex solved

That looks great. I could see you being able to make and sell quite a few of these
Hah! Took me more than a day, all hand work. -- Need to add a photo, the back side required a couple hours of careful slow grinding to match the profile of the firewall. Can't imagine that's quite the same for any two cars in the same year, let alone generically. It'd be tough to produce in bulk.