I think it's a very subjective thing... Do *you* think it would look good? Having it free-floating like that reminds me sort of the way the screens and keyboards were all jury-rigged on the ship in The Matrix. In my opinion, it can look kind of good if you like that look...
The one concern with what you're proposing, aside from the esthetics of the actual mounting, is the safety issue if you're having to look down at the screen while you're driving. You might be telling yourself right now, as you plan it, "Oh I'll just look at it when I'm stopped at a red light or stop sign" but in actuality you'll probably end up sneeking glances at it while driving, taking your eyes completely off the road. That could be not good for you, and for others on the road.
But as far as the look of it goes, if you think it will look good to you, don't worry too much about what other people will think of it.