The other potential failure outcomes involve selling the product at a loss, or tying up too much cash in it and having liquidity issues while stock moves. Valve's cash flow is likely excellent, we know they're not selling it at a loss and we know they aren't producing too many.

So overall, the possible outcomes all seem like different degrees of success.

Modifying the prompt and then trying it again did not lead to that self-verification loop and the output was unusable garbage.

I think the most important question is whether the system requires a regular automatic/manual transmission or forgoes one entirely. The Toyota planetary gear system forgoes one, as does the modern Honda and Nissan approaches. Not having a transmission in the traditional sense saves so much complexity that the overall system is net simpler imo even with the additional complexity from having a motor and engine.

Then there are systems that have a full automatic drivetrain and some extra clutches to couple to a motor-generator. And there's even systems with an electronically controlled manual transmission instead. Those systems are going to be incredibly complex and fragile.