Rental vehicles are held for a relatively short period and then sold into the used market. They are serviced on schedule, but they are driven by a constant stream of drivers with no stake in how the vehicle is treated.
Wear tends to be concentrated in the things that suffer from careless use: clutches, brakes, interior trim, wheels and bodywork edges. Mechanical maintenance is usually sound.
Registration under a rental company, particularly in a state where rental fleets concentrate, is the usual sign.
Why it matters
Ex-rental vehicles trade at a discount that is often larger than the actual difference in condition, which can make them decent value if you inspect carefully.
How to check it
Check the clutch and brakes specifically, look for kerbed wheels and scuffed bumper corners, and confirm servicing was actually carried out on schedule.
Does this apply to the car you are looking at?
Run the VIN or plate and see what is actually on record.
Related terms
Definitions are general guidance, not legal advice. Title rules, total loss thresholds and inspection requirements are set by each state and change over time, so confirm the position with the motor vehicle agency for the state the vehicle is titled in before relying on it.