I did not have any experience with Thrifty at MDW, but had some unpleasant experience with them at SDF recently. First, I arrived 20 minutes earlier and they claimed car was not ready and suggested that I could pay extra to upgrade to the next size. I declined and said I would come back in 20 minutes for my intermediate. As I was walking away, they told me my car was ready and then proceeded to offer me all kinds of additional insurances which I politely declined. The agent then told me she sure hoped I wouldn't wreck the car because my credit card company doesn't include liability insurance. As she handed me the rental contract she also told me I had to return the car to the same assigned parking spot and show a gas receipt proving that I filled up the tank within 10 miles of the airport. I don't think any other rental car companies have such policies. Anyway, I complied with all the instructions upon returning the car (my original spot was taken) but vowed never to rent from Thrifty again at any location no matter how big a discount they offer. I have always rented from Hertz and never encountered any problems, now they have my complete loyalty. I learned that good service is worth paying for. I hope my experience at Thrifty SDF Louisville is an isolated one and that you would have better luck at MDW.