Where do rental companies sale their cars?

Answer 1

I know that Enterprise keeps the top 5% of their vehicles for direct resale at Enterprise Car Sales locations (there is also a website where you can search for particular cars across the nation).

I cannot speak for other agencies, but in general fleet cars are auctioned and wind up at various used car dealerships. They are not necessarily high-mileage cars, since cars will be sold at times when an optimal price can be obtained, depending on market conditions for used cars. I have seen cars with as little as 1,000 miles on them be sold out of the fleet, because the market price is hot at the time.

In the United States, if you run a background check on a used car (such as AutoCheck), the report will state "FLEET" if the car has previously been part of a rental fleet or a corporate vehicle fleet.

Such cars are not necessarily inferior, since they will (for the most part -- depending on the company and the branch) have been maintained on a regular schedule (new cars nag you when they need oil changes and such).

In Enterprise's case, the best condition cars will be at their direct sale locations (Enterprise Car Sales). I do not know how other agencies handle their resales.