Don't do it. You have to take two busses to get there with a transfer at the Airport Rental Center and another 10-12 minute drive to their facility. The rental facility is poorly maintained - clearly nothing invested. The car we got had not been cleaned properly with water spots so thick on the mirrors you almost couldn't see through them. Employees were "uncaring in general" and it was just a bad experience.
I used to rent from FOX at Seattle weekly and they were great. Here - my advice is to go elsewhere. Not well executed AT ALL.
Don't waste your "Vegas time" on a bus driving to a car rental center.....