I have no problem with a low mileage rental, once you confirm as best you can it wasnt repainted anyplace. Bought a low mileage Mazda at the time still under factory warranty, 2012, now 95,000 miles, never needed a repair, car still runs great and got it crazy cheap, book value is still within a conservative $7000 of the purchase price.
Years back, daughter out of college, student loans etc. Bought a Ford Fiesta 2013 or 2014 maybe 2 years old at the time, low mileage again Enterprise, daughter is doing very well financially but still drives the car, I wish she would get a new one *LOL* same drill, never a repair.
Way back bought a 2008 Durango, same deal, year old during the financial meltdown of 2008/09 it was a dealer and cant be sure where it came from. Never a repair.
All three vehicles were under factory warranty when we bought, I think my daughter even got an extra year from Enterprise as my wife too or something like that.
I dont disagree that some rental cars are abused but since owning those cars above I have a theory that makes me more than comfortable buying a rental, if the right price. Not everyone drives and abuses rental cars, not even close, so I look at it this way. If you are buying a used car from one person how do you know they or a family member didnt constantly abuse the car during the entire time they owned it? You dont
Now buying a rental IF the terms, price and factory warranty are right for this simple reason. With multiple drivers of a rental car no one person is diving it, it's a whole mix of people. I would prefer this over one private driver and his family who abused the family owned car for the duration that he owned it or even a car dealer re-sale. No hard and fast rules but my thoughts, I look at everything when it's time and take it from there. I just feel now that we did it, I rather have a low mileage still under factory warranty rental knowing there wasnt one person or one family driving the vehicle the entire time, like you, I dont really know family people that tear up rental cars any more than private owners.