alt Hacker News>So if it's reliable enough, and there's also critical mass, then it doesn't matter much if the BYD drivetrain unit has easily-repairable components.
True, but swapping ICE engines was such an easy fix because of the modularity of powertrains that detached the messy hot rotating vibrating part(engine block) from the electronics and the rest.
These new ultra compact EV units are like if the ECU, catalytic converters, and starter motor would be built inside the engine block.
Here's a teardown of a recent BYD rear drive unit, performed by Paul Turnbull -- lead engineer at Munro and Associates. https://www.youtube.com/watch?v=4LfDuyqmsts
In very broad strokes: It's just a BLDC motor, some driver components for those spinny-bits, plus some water cooling passages and gears. A surprising number of these parts are identified as having been provided by Borg Warner.
That's nothing like what you describe at all.