I guess I couldnt recognise if it's a gap, or a bit of refractive index caused by thick plastic. And you clarified that there was a bit of a gap! It's my personal biggest bugbear on my own builds, with all the effort that one can put into the build, it some times ends up with thick glazing or poor fitting glazing (so it stands out to me). The pros on this site would make their own glazing out of acetate or plastic packaging which is more 'in scale however, I am not at that skill level yet! I'm still fighting a good car body paint finish...