I listed my family car on Turo earlier this year as an experiment. I posted it at a fairly high price because I figured it would be a little bit of a PITA to do it, especially since I've got two young children and the vehicle is always a mess.
So, after about 3 months of not hearing anything, and forgetting I'd ever put it on Turo, I suddenly got an offer for people wanting to rent it out for about 4 days for $350. I got my butt in gear and scrubbed the heck out of the car, put some local maps and other useful items they'd need in it, and delivered it to the airport for them.
The experience was really good. The car was the same as I gave it to them when they returned and they were easy to deal with overall.
We live in an area known for tourism, so I think it's pretty easy to get higher prices here. What we're wondering now is if we should do what you're talking about - buy a second vehicle and use it exclusively for Turo, with the idea of paying it off ridiculously fast and then just making money off of it on Turo or selling it... Still trying to decide if we should make the leap.