Although I'm not from Chicago, your thread tempted me to write something. I recommend you using public transport to travel around the city. You can buy Chicago Transit Authority pass for 24 hours for $5.5 and 72 hours for $14. With that pass you can ride train and bus in the city. Parking car is expensive. Furthermore, I don't think travelling in car is significantly faster than public transport in Chicago traffic. I am just sharing my experience.