So mine had a pretty hideous hood gap. I've spent quite a few hours trying to figure out what was wrong and on mine at least, I've found it. I was able to eliminate my gap very easily by leaving the grey tabs that connect both forearms together untabbed in truck mode. This twisted the forearm sections of the hood up toward the outside of the windshield giving it enough extra movement to close the gaps. The hood sections are now only held together by the tabs that go into the front grill. Mine now has negligible gap under the windshield.

I'm keen for someone else to give this a go and see what they find.

I'd post photos but I no longer have an image sharing account.