We reserved a rental car online using Priceline. When we arrived in Cancun to pick-up the car the Advantage rental agent seemed bothered that we used an online site to find the lowest price. They tried to get us to move up to a nicer car, and insisted we buy the added insurance (we had already purchased insurance online).
After refusing, it was clear that they did not appreciate the fact that we were trying to get the best price. The employees at the rental company also held us up nearly an hour trying to convince us to attend a timeshare sales pitch. Seemed fairly inappropriate considering we were just trying to get our car and begin our vacation.
The agent showed us the rental agreement and the price wasn't even close to what we had agreed to online. There was an airport fee (11%) and the currency conversion was another 8+% higher. The rates were way out of line with our paperwork. Everything was in Spanish, and I could only interpret enough to get by. The price had gone up roughly 25% from our original quote. That's much more than missing an 11% fee. It bumped the price up enough to make Advantage higher than any of the competitors we shopped online. Whatever, I figured it was not worth ruining our vacation about.
When we returned 10 days later they asked if we had attended the sales seminar. After telling them that we could not attend (we never intended to), their demeanor changed. They were once again irritable. The agent inspecting the vehicle pointed out what was an almost indistinguishable mark (he referred to as a dent) on the rim. I had not identified any rim damage when we picked up the car, and I admit I never even looked at the rims. We only inspected the body for damage. Anyway, the mark was on the drivers side which is impossible to hit because only the passengers side pulls up to the curb. Anyway, they held us up and insisted we pay on the spot.
It turns out that we had to pay 40% more than the original online quote. Beware of Advantage. They are a subsidiary of Hertz. My experience has been that Hertz is always more expensive than the competitors. I thought Advantage was their economical counterpart, perhaps that assumption was incorrect. The slogan "We'll pick you up", should read "We'll rip you off".