I did this at Budget MCI, and let me tell you, it was like rocket science combined with brain surgery to get the counter agents to figure out how to price me correctly. I said I was picking up 30 minutes early but would drop off well before 24 hours. I always say this ahead of time for precisely this reason. It priced me double anyway. Double. I refused to leave until it was repriced. Three agents, I kid you not. Three! And 45 minutes--my flight there was only an hour of flying time!--to fix it.

Then I was scolded for booking it for a later time. I said, "but if I did not pick up because my plane was late, you might have given my car away," and I pointed to the "we have a shortage of cars sign" still there from Covid. The agent said: "You're not wrong."
This should be automatic, like something in all their computers. It's not.

This was about a year ago now, and that Budget is not part of the corporate owned, so YMMV, but it was a nightmare.