You have to pay for parking soon if you don't have a Caesars card (of any level):
The pay for parking kiosk is to the left of the Guard's desk.
The Rewards booth to sign up for a free players card and get free parking is on the right side of the Guard's desk.
Can't believe Horseshoe is investing so much in hardware (ie: gates and license plate cameras at each garage entrance and exit) just to get people to sign up?