Remember if you are travelling the rental car shortage is real.
I have known a few people who rented via Expedia, Kayak or other 3rd party websites who showed up at counter and were told their reservation was cancelled and to enjoy using Uber for the week.
Rental car companies sold off a bunch of inventory last year to help mitigate revenue losses and car manufacturers have reduced their passenger car and smaller SUV production lines due to computer chip shortages. Manufacturers are prioritizing high profit models like big SUV's and trucks over lower profit vehicles which typically end up at rental car companies.
Best bet is to rent directly through the rental car agencies.