General Motors' next major profit engine kicks in after the vehicle leaves the lot. OnStar and Super Cruise are becoming serious sources of recurring, high-margin revenue, with OnStar alone generating roughly $800 million in the second quarter. Once the software is built into the vehicle, the economics are hard for automakers to ignore. The challenge is convincing drivers that features they already associate with their car are worth another monthly payment. At $40 or $50, Super Cruise may feel like an easy yes. Push that number too far, and the subscription starts competing with the car payment itself. Watch the full episode on our channel.