Rick, no pain, more of an awareness of pressure. Still felt it with the cotton in my ears so now I'm wondering if it's anything real or just an awareness of being exposed to the elements.
Tom, I've thought about doing the same thing. My Cobra's got a full width roll bar and I've got a sheet of lexan in the garage. The lexan is pretty thin (3/16"), I wonder if it'd hold up to the wind.
Oil, good point!
Jamie, oh, I think I'll get over the issue. Fifth gear is great fun, 65 at just a tick over idle. I'm really wanting to see what 4000 rpm in 5th feels like!
Thanks everyone for the suggestions. Nobody else has noted similar discomfort so I'm going to just continue to put on the miles and see if the discomfort has more to do with driving an unfamiliar covertable.