I also found that the factory did not cut the ultracote(?) and seal around the huge slots that the wings slide into.
To tack the coating down..I used some stixit and a small iron and folded the coating back under the side panels.
I have never had a plane where this was NOT ALREADY done! If you look at the attached picture from Nitro website, it is obvious
that the slots are just covered over. (see green circle) If you do not do a good job of tacking the coating down..I would expect
the coating to start peeling after numerous wing removals/attachments.

BIHAMBY Use your common sense and care with this build. DO NOT take the manual as being the build bible as it is errored in many areas.
I hope the areas I have alerted you to help on your build and good luck!