Very NICE work!
Two thing though; on the underside, you've painted most of the access panels darker. I understand what you doing but they end up looking recessed quite a bit from the surface of the wing. They should be flush with the surface or at worst a little raised. Maybe try taking some of the darkness off of them and maybe putting your highlighted edge on the edges of the access panels instead?
Also, your fabric looks really cool but it doesn't look anything like the real aircraft fabric at all.

These aren't D9 wings but here's my solution on the access panels and fabric-
Attachment 1010
Not better but more realistic on those 2 points even though my fabric has WAY too much detail considering how smooth these were in real life :P