I almost used Turo once, but the whole thing seemed very ambiguous wrt liability, exact condition of the vehicle, etc. I don't drive normally, so am I even insured? The car owner's insurance likely covers lending the car out, but probably not renting it out, and they likely aren't even aware of that.

The information asymmetry and friction with these niche p2p sharing services just isn't worth it. You're basically learning the rules of an entirely new industry with each one - a significant amount of mental bandwidth to discover whether or not it will even work for what you need.

Sharegrid reached out to me once (because I was selling a camera on Craigslist). I looked over the site for about an hour and still would have had no idea about this "voluntary parting" issue.