The problem is more with Kayak not clearly stating
Pros: Very helpful and sympathetic AVIS staff. Reservation was cancelled at the desk with minimal issues.
Cons: I can't remember renting a car and being charged a mileage fee above and beyond the base price, taxes and other fees that are usually included in the quoted total. Even then, when I was presented with the "estimated cost" that substantially exceeded the price quoted on Kayak, Avis was only "estimating" 80 miles @ $0.30/mile when the rental agreement clearly stated that the car would be returned at a location >300 miles away! Very deceptive on both Kayak and Avis' parts! Thankfully, I had the option of driving my own vehicle and the reservation was cancelled.