Stuntman's install was good, and the chequer plate good/bad debate probably does not apply when its out of site and painted black inside the cab.
As mentioned in the original thread though, I would serioulsy not want to find that in the way of my forhead in the event of an accident. Head linings and trim are made of soft plastic and impact absorbing materials for a reason.
Admittedly it may never happen, but why chance living the rest of your life with an aquired brain injury because of a mod you made to your truck?
My advice would be to mount it somwhere in your eyeline, where you dont have to root behind seats or under dash boards to turn on/change channels etc.
I did have one mounted in the map pocket which made me nervous to be honest and made it difficult to see the LCD display when it was backlit in the dark, my next will be centrally mounted, slightly angled towards the driver. It may not look the best, most symmetrical install but it will be (hopefully) safe and functional.
Stu.