Something like this. Do it right and you may be able to find a spot where you can remove the bracket and tablet all together, but be prepared for your dash to deteriorate over time. In my beater I didn't care; in my Caddy - it started to crack the woodgrain. I found a slot between the radio and the dash that was better, but the leather wrapped foam area around the radio became deformed.
Been there done that. I've been using tablets in my cars for over 10 years. The early ones had no docks so I did like Breaker021 and built a bracket to hold it and ran all the wires up to it however I could. I have since graduated to the minidock and now a full dock hidden away in the dash.
You can do it. Two hints of caution - if you find an area to use, use all the depth behind the dash that you can. It will help immensely with shock prevention. Second, build your bracket out of the strongest material you can get. I started with aluminum that I could bend by hand to create my mold/prototype and took it to a metals shop and had them use their 400K machines to cut and bend 1/8th inch stainless steel for the production bracket.