Availability, price, what documents are needed, can be paid by card, there is delivery at the airport. These are the questions you get dozens of times a week if you have an active fleet.
A well-structured website responds to all of this before the customer contacts you. Fleet Page show available cars, prices, and amenities. The contact page or a FAQ section resolves the rest of the FAQs.
When information is clear and accessible, customers have more confidence and the conversion rate increases visibly. No more wasting time explaining the same thing a hundred times.