This option clearly comes with a certain amount of risk, but there are a growing number of services dedicated to allowing you to essentially lease out your car while you aren't using it yourself. The concept is that rather than renting a car from a traditional car rental agency, you can rent from a fleet of personal vehicles.
Turo, for example, allows you to list your car as a "local host" at rates they purport to be 35% less than traditional agencies. When you list your car to be rented via Turo, the company sets the car's rental price based on market value, your location, the time of year, and "other data sets," or you can manually set your own per-day price. By that token, "nicer" and newer vehicles would command higher rates.
And while there is some risk, Turo is insured, covering local car hosts with up to $1 million in liability insurance — and it's completely free to list your car on Turo, with no monthly fees or buy-in.