On Friday, January 1, 2016 at 11:40:27 PM UTC, wrote:
the texture of the panel surface also reduces the surface area

The texture of the surface you are applying the label to is the problem. You need a thicker adhesive to get down into all the grooves. 3M468 transfer adhesive is five thousands of an inch thick and 3M467 is two thousands. There are other products that will give the same performance.