Best paint or treatment for glare reduction?

Hi,

I have a couple of 'hot spots' in the anti-reflective coating forward
of the instrument panel on my Ventus. In particular, the outline of
the forward vent shows up quite nicely in my forward view as a
reflection on the canopy. Almost like a gunsight - useful for locking
up on that glider ahead, but frustrating with no ammo! ;-).

Anyone know a good way of toning down the reflections? I have tried
using a black 'Sharpie' pen, but this doesn't seem to have as much
effect - too thin and/or too reflective. Same with black electrical
tape, with the added disadvantage of having to deal with tape residue.

Any help would be appreciated.

Frank (TA)