I'll throw my hat in first with:
8424 miles in 15 days
Drove approx MCI-YEV-FAI-MCI
Grand Marquis with about 3k miles on it at the start
On returning the car (non-airport), the guy checked the odometer came inside and started typing on the computer...paused staring at the screen, then without speaking, grabbed the keys and went back outside and checked the odometer again. He came back inside and asked me how many weeks I'd had the car. Then said "wow, that's a lot of miles", shrugged, and gave me my receipt.