I think I know who is working on this. The following video is a lecture at Stanford Unv by Senior Mechanical Engineer Dave Duff from Tesla, recorded in Nov 2012. In the video at 18:00 he shows small robot modules that attach to each other to perform tasks. Watch from 18:00 to 18:28 Stanford Seminar - Dave Duff, Telsa Motors - YouTube
1) Self Driving Cars
2) Automatically "ejecting" the charging cable once the vehicle is fully charged.
3) Notifying an owner that their vehicle is fully charged, and reminding them to either "summon it" or pick it up. Also, Tesla could impose a fee for people who forget or choose to park their Tesla for more than 1-2 hours.