I used to rent a lot, at my old companies expense from a local Hertz office. I got chummy with some of the workers and used to ask a lot of questions about the business.
Service: Yes, the cars got oil changes at the recommended interval. This means that if the manufacturer said it could go 10k miles then they took it all 10k miles. Not great but no worse than vehicles owned by the average masses. Maybe better than lease holders.
Turn in: There was no set mileage point where the cars were retired from rental service. It was explained that there is an entire financial dept that manages this "turn-in." Often, there might be a huge purchase order for Hertz to buy Camrys at a super cheap price but that purchase comes with stipulations that Hertz can not release them for a certain time period. I think Toyota is just dictating some terms so there is not a giant flood of low mile, used Camrys coming onto the market.
My people said they saw cars like Camrys get "turned-in" with less than 4k miles and I have had rental cars with 35k miles on them too.
Wreck repair: Hertz does not send much to the body shop. Typically only the most minor of stuff. If it is more major damage, Hertz will auction off the car. Hertz will then hit the "at fault" party for "loss of use". Something like they will charge the "at fault" party for rental revenue not gained while the car is down.
This auctioned off car was not "salvaged" but rather Hertz just does not want to take the time managing repairs. If you find this car on a used car lot it might not show the damage on a carfax report especially if there was not a police report. The damage could be a simple as just a fender and bumper cover.
Buying used rental:
Most all cars found on used car lots that are about 1.5 model year old or newer are former rental cars. I have a Chevy dealer here who loves this kind of stuff. He will put up billboards for 2016 Impalas starting at $15,999 stating 35 available and the fine print will read (previously owned).
Restating the issues of wrecked cars being auctioned, I would be fearful of a used car with very, very few miles like 4k. I would suspect that this car was wrecked and then auctioned off. Look closely for damage.
I would be more comfortable finding a used rental with 15k miles. It likely served out its typical rental life with no damage.
The mid sized models will get the most miles and maybe the most abuse since they are the most common rentals. When it comes to premium models, the rental rates are much higher and i would thing this increased "cover charge" might weed out some of the worst abusers and over the rental life of the car, it likely has seen fewer miles.
The rental companies charge a ton to rent a minivan. Many of them get loaded with a lot of highway miles since they are used to haul large groups on vacations. Combine these two things and some former rental minivans can be a good value.
In summary, buying a used rental is a crapshoot just like buying any used car. Also, just because you are buying from a Chevy dealership and not Hertz's own lot does not assure you that you are not getting a former rental car.
