Where can I find rental marketplaces?

I think I know the type of website you are remembering. It is basically a rental marketplace where many individual cars are listed and different providers can offer vehicles through the same platform. I came across https://renty.tr/ while searching for something similar. The useful part is that you can browse the catalog and compare rental conditions instead of simply seeing a list of companies. If your memory is of a site where you could scroll through lots of actual cars, select dates, and compare offers, this is worth taking a look at.