Mastiff hair in car?

We went of a road trip with our English Mastiff riding in the back of our SUV. Of course there was dog hair from him laying back there, but now it will not come out. Tape, pet lint rollers and vacuuming multiple times still have not made mush of a difference. Its like the hair has woven itself into the actual carpeting, and its sticking like velcro! We have even had the car detailed and the detailing people could not even get it out. If anyone has had experience with or a solution for getting stubborn dog hair out of the car upholstery please share your advice! Thanks!!