The rental process at Cancun airport is quite efficient and the service is warm. There's no excessive upselling or troublesome tactics. I think the main reason is the high traffic here, they don't have the time or need to earn money in such a way. Additionally, rental companies are close to each other, making the competition fierce. Bad service would lead to losing customers.

Waited over an hour. Refused our insurance so had to pay £150 or not be allowed to take the car