My children like to watch their tablets in the car. I bought tablet holders but they were not brilliant. Struggled to find something decent online. Then by chance I noticed these for Skoda cars http://www.theskodashop.co.uk/product/Smart_Holder_–_multimedia_holder_3V0061129-3V0061128 So I bought them and they cost about £20 each. Each to fit to rear head rests, solid and good adjustability. Highly recommend as Audi don't do them but just sell their expensive system with tablets included.