Please don't be offended by this question...
Why do you want TV in a roadster? My previous Z4 came with the TV function installed, but the ONLY time I used it was when stuck in a massive tailback on the A1. The factory fitted option disables the picture (sound stays on) as soon as you take the brake off, as the law dictates. If you intend to not enable this function, then you would have a distraction infinitely worse than someone who uses their mobile 'hands on'. Also, be aware that the picture is just about impossible to see with the roof down because of the glare, and not much better when the roof is closed.