To make the concept come to life, I wrote a story about a fictitious solo business traveler, Sarah, who has a few hours to kill in the evening in San Francisco by doing a tour of the city. The solution is an assistant in an autonomous car that understands Sarah and anticipates her needs. It also has a bit of snark to its personality, something Sarah appreciates.
Figure: Meet Sarah
Writing and rewriting a story is a quick way to prototype. I usually start out almost all of my design work by writing first. I went through a couple of drafts first and later sketched a few screens on paper before quickly turning to mocking up screens (at that time) in Sketch. The digital work in turn helped me refine the story further and add some elements of amusement and delight.