PERHAPS the fact that the customer is updating the firmware themselves is something new. But as others have pointed-out, car manufacturers have been updating firmware in engine and other onboard computers for years.
Human-Machine Interface Engineer? Not new either. Let me tell you how I turned some line workers into Human-Machine Interface Engineers 30 years ago...
I was working for a small company in Michigan that made measurement and control systems used on automotive assembly lines. We were working on a system for a Bendix axle plant. It read a Brinell (hardness) gauge, and controlled the movement of the part through the station, application of the gauge, good/bad paint spray, etc.
The company was perpetually behind, they had one and a half software people (I was the one - the other was a hardware guy that dabbled), and they didn't want to bother me about this job until I'd finished the prior one. So, I finish up this job and they tell me they've got this new job for me to do, and they're sending me to Ohio the next day on the primary contractor's private plane.
They had the hardware put together. They told the client they were sending two guys to wire-in the system. No software had been written or designed. I didn't even know what it was supposed to do. They briefed me...
We arrive at the plant and the guy we meet starts screaming at us. We were two days late. We didn't KNOW that we were two days late, but we were apparently two days late.
While my co-worker started wiring-in the the box, I set up my Altair (yes, really) on the plant floor next to the line. So, for two weeks, I sat there with this deafening noise designing and writing code. The line was down, of course, and the two workers responsible for it had to stand around twiddling their thumbs.
You haven't felt pressure till you've shown-up at an axle plant two days late to write software on the plant floor from scratch, with the line down, and two monkeys hovering around twiddling their thumbs.
The line workers might have had some light maintenance tasks, but otherwise they didn't have anything to do, so they helped out. Sometimes we need them to operate the equipment, etc.
We had a panel with a small LCD display (a few characters) and a bunch of big, industrial buttons in neat rows and columns. And no design. At all. (OK, I mean, we knew what we needed to do with the gauges and solenoids. We knew the operating sequence of the line. But there was no per-determined UI design.)
So in a leap of faith I ask the guys: "how do you want this to work?" Why not? These were they guys that have to work the machine every day. Who better to do the UI design?
They were delighted. I made the buttons work the way the line workers thought the buttons should work. I made the display show messages that were meaningful to them. It really helped to smooth-over the situation of us arriving late with nothing but a gutless box that did nothing to wire-in...