I just picked up my exige yesterday and thought it would be interesting to contribute - it’s a bad photo and doesn’t show it well but mine doesn’t appear to have a seal at all!
IMG_20200618_131258142 by zimbarbaluba, on Flickr
Cheers Andy, congrats on the new car! That really doesn’t surprise me, of the pictures I’ve seen it seems like no two cars are alike! Seal was cheap enough from Deroure though if you feel like addressing it 
was it easy enough to apply? Did you need to use some kind of glue as well?
Yeah dead easy, it came as self-adhesive so was just a backing strip to remove then stick it on. I used the bottom edge of the roof as a guide to line it up and it seems straight enough to me. 
[mention]Fonzey[/mention] What was the part number of the seal you ordered to run all the way across please? Mine is coming away and would like to order a new one, but want the one that goes all the way around the Mohawk.
B117U6007F
Does it act as a water seal between the two panels as well?
Yeah sort of, but there’s just a rain gutter under there anyway which is sealed by a different seal - so if this bit of seal was totally missing you wouldn’t get any water ingress to the cabin, it would just pool up a bit in the roof rain gutter.
On an SC car though it would mean that your IC ducting would fill with water though, maybe a good heatsoak fix 
In very heavy rain and at motorway speeds I’ve had a bit of water come in at the top rear corner of the window, I wondered if it was because my car doesn’t have this seal at all, or perhaps the window needs adjusting.
Almost certainly this!