I have only rented a car a few times recently, for skiing and hiking far from home, but I like the idea of a smoother experience and I love anything that creates less waste :)

https://www.drivecarve.com/search?startDate=2019-11-8_3-00pm...

^^ I know it's 2019 and this is expected but I really appreciate this URL structure for search results. I have spent a lot of time working on booking sites and it used to frustrate me to no end that some projects used a very un-friendly URL structure. This will help your marketing team so, so much over time.

I'll offer some critique of the booking process that you probably already know of: travel is highly dependent on trust signals and push mechanisms like Best Purchase Guarantees, People Looking at This Hotel, countdowns, etc. Some I find gross while others necessary. I think you could look at the booking experience and find plenty of room to grow there. Right now, the car experience feels barren and fake to me. I bet there are some things you will find very helpful, like MPG, etc. so it's just about testing those assumptions.

Best of luck!