Well, I mostly use Uber for city wide travel but when I'm traveling outside the country I often get into trouble of hiring a car online because the price spikes all the time. I then have to hire cars the traditional way when I land on airport, even then sometimes I face problems.
Turo is a good option just like Uber but money saving is not its feat. I didn't find much of a difference. So based on my experience, if you want to travel outside of your country, hire 1 to 2 weeks before. Since, I do online shopping most of the time even for travels so I own a VPN with virtual prepaid cards. It helps me get rid of country specific websites and price changes, plus sometimes I get discounts as well. I might not be able to describe it well
. I learned this trick on the case study by a VPN company regarding car rental. Here's the self explanatory study: https://www.purevpn.com/blog/cheap-car-rental-tips/