carpeting new or used (Cap Hill/CD)

Hi, I need a piece of carpeting around 5' x 7' (could be bigger and we could cut to size, or even a little smaller), new or used (but in decent condition). It's going to be put in the back of a mini-van for 2 big dogs to sit/lay on during outings so it's fine if coming from a home with pets. Thanks so much!