I seem to be thinking a lot about the future of automatic cars these days. Already we're seeing cars in Japan that can park themselves in a tight parallel parking spot, and this leads me to think that the next market for the technology, after the basic automatic highway, won't be the city street but the parking lot.
Parking lots eat a lot of space, and where the land is expensive, automatic cars will offer automatic valet parking. Drive to the mall/office/whatever, enter the automatic lane and be whisked to the door. Get out and your car will run off and park itself efficiently, possibly some distance from the building. (In the future with more fully automatic cars trusted on city streets, it might rent itself out as an autotaxi.)
When ready to leave, use your cell phone to tell the car to come to the nearest door, and it will be waiting there. Obviously that's a great convenience, but the real reason this will happen is it saves a bundle for the building/parking lot, because they can park more cars in the same space, or even park cars offsite. Whatever cost is needed to bury guide-wires or other transponders is easily justified by the efficiency gain, especially in downtown multi-story lots, many of which already justify the cost of humans to do the work.
Later, however, I will reveal the big catch that may keep us from this.