Since the DC Union Station thread has been helpful to me as a visitor, I thought I'd start a thread about this location. The garage entrance is on La Salle, but the counter is on the Clark Street side. It is right under the CTA Clark/Lake stop. It is a joint National/Alamo location with a shared inventory - space for about 25-30 cars.

Cons:
- They have a lot of novice customers.
- They have no fuel pumps, so you get cars with less than a fulll tank. This will be a hassle if you're returning elsewhere. The lady in front of me ended up with a car with only a quarter tank, fortunately she didn't have to go far and she negotiated paying $10 to bring the car back empty. Given that gas at the nearest station is $3.79/gallon right now, she probably got a good deal.
- Not open 24/7. Don't think they're open on Sunday at all.
- Generally higher weekend base rates than ORD/MDW, mostly because they don't count in the last minute specials.

Pros:
- Much lower weekday rates than ORD/MDW. I've found $36-$48/day when looking for various trips.
- Minimal taxes. No $4-$8/day airport fee, for example.
- The staff can figure out when you are NOT a novice customer, and don't give you a lot of nonsense upsell talk.
- I had no problem getting upgraded on my FCAR rental to a full leather/sunroof/Sirius Grand Cherokee. All I said was "Sure, I'll take the Charger, unless you have an SUV you'd like to unload on me..." For 400 miles of driving, I'm happy to pay the 7-8 mpg penalty in extra gas (so about $23 for my three-day rental) for a MUCH better ride.