To mount an Emergency Dash light

I have a new 2012 A3 TDi, I want to mount a Emergency light to the front dashboard just between the air vents. I had two sided tape that did not last, and the dealer gave me some sort of black putty which just left a black mark on the dash and didn't hold the weight of the light. There is a metal mounting system that must get stuck to the dashboard and the light is attached to that using a magnet. I have a clear epoxy I was going to use, I plan to keep the car for about 8 ot 9 years if I can. Will the expoxy work? Or should I try to get stronger two sided tape?
KW