The worst moment in car rental: a customer arrives to collect and finds the car with someone else. Phone and notebook booking makes that mistake likely, especially in season. A calendar per car closes the door on double-booking for good.
Customers want the final price before confirming: rental, insurance, extras and deposit. When all of that appears in the booking itself, there are no surprises at pickup, and the long WhatsApp back-and-forth disappears.
At return, scratches are the biggest source of dispute. Photo inspections at pickup and return, recorded with the date, protect both sides. And reports showing each car's utilisation tell you which category to grow and which to sell.