When Ivan Drury, an auto industry analyst with Edmunds.com, sought to buy a used car last year he purchased a 2018 Ford Fusion Hybrid from Avis.

He had previously done an analysis of used car prices in 2017 for his job and found, to his surprise, that rental car companies were selling their own used cars at much lower prices than other used car dealers.

Depending on the specific model, buying directly from a rental company rather than a used car dealer could save anywhere from 5% to 15%, he found.

"In some instances," he said, "the discounts are just so good, I was kind of floored."

Take advantage of tryout periods

All of the major car rental companies -- Hertz, Enterprise, Alamo Avis, Budget and others -- list their used rental cars for sale on their web sites.

Some used cars are just better and more reliable than others no matter where they're purchased.

He also recommends buying from one of the major rental car companies rather than a smaller operation.

That's because smaller rental car companies may be selling cars that were already used when they bought them.

Check out your financing options

Shoppers should also research their financing options before buying, Linkov said.