I work in automotive embedded. And yes, the field is bloated. Yes, things could be more efficient. But even if all those problems went away, I still don't think it's feasible building one-off ECU's for usage in a friend's car.
Those things take a great amount of effort and time. The complexity is pretty big. Granted, I mostly work on instrument clusters, and I believe they are one of the biggest systems in the car, but the complexity is huge. I found it hard to carry the mental model of the whole system in my head.
After-market ECU's are deff possible, because you do a couple thousands of units at a time. But doing it for one ECU, I think not. Not if you put an upper-cap on the effort you are willing to expend. You're probably better off just buying a new car at that point.
Those things take a great amount of effort and time. The complexity is pretty big. Granted, I mostly work on instrument clusters, and I believe they are one of the biggest systems in the car, but the complexity is huge. I found it hard to carry the mental model of the whole system in my head.
After-market ECU's are deff possible, because you do a couple thousands of units at a time. But doing it for one ECU, I think not. Not if you put an upper-cap on the effort you are willing to expend. You're probably better off just buying a new car at that point.