Probably over 2,500 in a Ford Fusion, driving from MDT to MCO for a long weekend. However, in two different cars, with about a week break in between rentals, probably closer to 4,000 or 5,000. They were insurance rentals, and we racked up the miles because we could.
Picked up the first one four days after we moved into our house, because a girl making a right out of a gas station swung it wide, and hit my Jeep, from behind the driver's side front tire all the way back to the driver's side rear tire, while I was stopped and fully in my left-turn lane, because her coffee spilled. Easiest insurance claim ever! She took responsibility at the scene and was cited. Claims person called me, I related what happened, five minutes later, they called me back and said, "We're accepting full liability. Where do you want us to send the rental authorization?"
Had that car for 7 weeks before picking up my Jeep. Picked it up on the Tuesday before Christmas, that Sunday, the driver's side rear wheel fell off of the vehicle. It actually fell out of the differential or whatever that big ball thing is.

If you've heard Ron White's tire story, you know what I told Mr. Kipper. Picked up another rental car that Monday. Had that one for a month, including the drive to MCO.