Nolan's phrase of the day was, "And how do we solve that?"

About an hour into the presentation, a third chair was brought on stage and Kimbal Musk, Elon's brother and an entrepreneur in the food-access space, joined in -- wearing a cowboy hat and with a guitar in tow. With his help (and the appearance of a second cowboy hat for Elon), the entire conversation closed out with a sing-along. This is SXSW, after all.

Catch up on the latest news from SXSW 2018 right here.