When we first rented the vehicle, we were told we had to purchase extra insurance so we took the highest coverage possible as the attendant told us that we would be covered for everything, When we went out to get the car, we noticed that the tire pressure light was on so we pointed it out to the attendant. He took the car to the back and he told us he filled the tire but not to worry about the light, because the light did not go off. We checked the rear tires which were worn but ok to drive on, and we checked the front driver side tire and it was brand new so we assumed that both front tires had been changed. We drove to our rental property in LaFortuna and drove around the area for a couple of days. We then noticed that there was a wobble in the wheel so when we checked it out we saw that the tire on the front passenger side was totally worn out and had threads showing - this is the one tire that we did not check when we picked up the car. We drove to the AVIS office in LaFortuna and he strongly suggested that we change the tire as it was dangerous to continue driving on the tire as it was. However, he did not have one in the office. So we put the spare tire on the car. We returned the next day and he told us he was unable to get a new tire for us but he could get us a different rental vehicle. We returned the following day to exchange our vehicle - the new vehicle was not 4 wheel drive and it was smaller than our original vehicle but we agreed to swap it. They did not offer to charge us less because we were getting less of a vehicle but they told us they would be charging us for the tire. So we had to pay a higher price for less of a vehicle plus the cost of a new tire even though the tire was in that shape when we originally drove away with the car. They accused us of overturning the wheel on the front passenger side. One of the men in our party is a mechanic and he asked them to explain how it is possible to spin only one tire on an AWD, they just kept repeating that we had to pay for the tire. We have been trying to talk to someone who can explain why the tire is not covered by our insurance and why we had to pay for it, but no one can answer us. So disappointing.