Hello. I'm been reading many topics that have been posted and I want to thank all of you who recommended the California Duster. I purchased the large one for the outside of the car & the small one for the dash. They work great. Now I need some help with the following: I am a mobile veterinarian and sometimes transport pets (some too large for a crate) as well as, my own dog who travels with me daily. I'm looking for a seat cover that is 1) waterproof 2) machine washable 3) easy to put on and take off 4) sturdy and last, but not least, 5) comfortable. Any comments would be appreciated. The next thing I need advice on is maintenance. My Prius owner's manual says the first oil change is due at 5,000 miles but my dealership suggests it to be done at every 3,700 miles. If I don't follow the dealership's recommendation will it void the warranty? Thank you. Susan.