Had National windscreens replace a screen for me a month or two back, I had excessive wind noise and howling at speed. Didn't complain at first as I believed it to be trims and scuttle which I've since sorted. But now noticed the howling is definitely windscreen and can feel ingress of air from edge. Has anyone got any experience of similar issues?

Should be a straight forward case of contacting them to put right.

A windscreen should fit tight for many years, certainly until the rubbers seals start to perish.

Just book it in to be rectified. I'm sure they won't argue