This post came to my attention, and has named our company, so I thought I would respond (and hopefully turn down the volume on the rush to judgement here):
The OP took the van to Burning Man in the Nevada Desert (off road is prohibited under the contract btw, and our website specifically says Burning Man is prohibited). Upon return the van was covered in dust inside and out - inside cupholders, smushed into speaker grills, underneath seats, in carpets, and everywhere you could possibly look (and many places you couldn’t). I should mention that the bill the OP is upset about also includes the extra charges we incurred from the detail shop for a complete shampoo and getting the dust out of everything.
The engine was of course also completely covered in dust. We took the vehicle to a dealer mechanic within hours of the vehicle being returned in order to make sure that everything was ok. It was the dealer mechanic at Courtesy Ford who gave the service recommendations (air filter, trans flush, steering fluid flush, and replace serpentine belt) based on the level of dust. As our clients don’t typically take our vehicles into the desert, we didn’t have any reason to doubt the recommendation, so we authorized the work and paid for it.
For those who were thinking this was a backhanded way of having the OP pay for scheduled maintenance: the vehicle had received a complete tuneup (total over $2700) just a month prior to the OP’s rental. So there was no scheduled maintenance due for quite a long time.
Based on the conversation here I reached back to the service adviser who told me the steering system in an Econoline E350 is not a “completely closed” system, it does vent to outside air, and it is possible for dust to get in through these vents and contaminate the system (particularly in an extremely dusty environment like Burning Man - where the dust is the consistency of baby powder). Burning man is also prone to dust storms, so it’s not like OP just went up a dirt road for an hour or two. You can see some pictures here to get a sense of how extreme these conditions are: http://bit.ly/1zkX8j5
OP signed the contract, and agreed to be responsible for returning the vehicle in the same condition he rented it. As a van rental company we have to prioritize safety, and we have tremendous liability exposure if we do not. If a mechanic tells us that the steering could be potentially adversely affected by dust, we have to address that issue. It really isn’t optional.