1) If this guy was trolling the area for some time, he sure has a lot of free time on his hands in the middle of the day.
2) He may drive more than one car, or buy and sell cars constantly to swap them out.
3) The intersection of Goodwin & Springfield has traffic cams on Goodwin itself, so I hope they viewed those and others to see if they can read the license plate number (front or back) along any route he may have taken. I have a feeling though, that the license plates aren't going to connect to that car.
4) (probably not relevant, but just in case: Events that occurred June 9-12
The People's Summit, June 9-11, Chicago, IL
Spring Awakening Music Festival, June 9-11 - Addams Medil Park
Chicago Blues Festival, June 9-11, Millennium Park
Redhead Days, June 10-11, Everts Park
U.S. Log Rolling Open National Tournament, June 10, Orland Park/ZLake Sedgewick
Noval Soul Quartet jazz and pop group, June 11, corner of Des Plaines and Lockport
Ben Seidman - Magician, June 11, North Shore Congregation Israel at the synagogue in Glencoe
St. Catherine of Alexandria Carnival, June 7-11, Oak Lawn
Groovy 70s Party, June 12, Indian Boundary Park, Frankfort