Turo's 'Carculator' lets you see potential earnings from renting your ride
Of course, it all depends on how willing you are to part with your wheels, and how often.

Peer-to-peer car sharing -- Airbnb for cars, essentially -- is a relatively new concept, and its biggest proponent right now is Turo. If you've thought about joining the service, but weren't sure what kind of money could or couldn't be made, Turo now has a tool for that.
Turo's "Carculator" (clever name) is pretty straightforward -- plug in a year, make, model and location, and it will spit out your possible potential earnings with an estimate of how often it would be rented out. It calculates this estimate by looking at data from rentals that have already happened, so it's not just pulling figures from thin air.
Considering my station wagon isn't exactly an objet d'art, I'm not surprised its earnings potential is lower than the examples Turo provided in this image.
If the number is hilariously low, perhaps you won't get much out of renting on Turo, but if you have a highly sought-after car, it might replace your pupils with dollar signs, cartoon-style.
As a quick example, I looked up my personal car, a 2016 Volkswagen Golf SportWagen SEL. Detroit wasn't listed as a location, so I just used the national average. According to that information (with my specific trim selected), my VW could earn $551 per month, which is slightly under my monthly payment. That number is calculated based on a possible $41 in earnings per day spent rented, and the Carculator estimated I'd be able to pawn my wagon off on people about 13 days each month.
Of course, that won't work for me, because the car is tied up in daily commutes every weekday, but when it comes to sports cars and other vehicles that are only used occasionally, it could very well be a solid stream of supplemental income.