New tailgate.....

[Taily]

I believe there is no adjustment to move the bottom of the tailgate in/ out ,only up-down & left/right..
Evenif there was with a BOW like that the corners would hit before the middle got close..
I think it's the way there pressed together, Too much pressure on the ends first is possibly bowing the inner first.
But who really knows until they look at the issue properly..

I understamd what you're saying (and you're right, my own tailgate is very close at the ends) but if you saw some of the ways we used to need to adjust some of these things in Holden dealerships back in the 80's you might see where I'm coming from. It is possible to adjust in and out by reworking the hinge point up and then lowering the attach point.

Knot up a pair of fairly sizeable rags and insert them inside the ends of the gate and go to close the gate... Get my drift?

All part of everyday life in PD depts in dealerships and panel shops back then. It was only really the early 90's Australian manufacturers got their acts together (so to speak) and started to get some reasonable panel fit.