The New Beetle hatch lid has an embedded elongated and slightly curved third brake light that can be relocated to the fiberglass section above the cabin rear window. The light’s curve closely matches the profile of the roof line.
One advantage of this relocation is that the existing wiring harness can be reused without any modification.
Position the cutout third brake light metal frame harvested from the hatch lid on the fiberglass cab window section and secure using two wood screws at either end. Scribe the ends and then sand fiberglass to make small indents so that the metal ends fit flush with the fiberglass. Using the metal frame as a template, scribe and cut out curved opening.
Roughen the fiberglass surface around the cutout and screw on the metal frame. Insert the plastic brake light fixture and check the gaps on the metal frame. It may be necessary to insert wedges to get the curvature just right.
With the curvature set, fill the cavity with bondo. Then complete the contour to blend in the metal frame.