[Scarebird]

My trunk lid always had a heavy gap on the driver's side; 0.340" vs 0.190". Reinstalling the trunk lid I note that is all there is - any tricks other than elongating the already large hinge hole to even this up?

[OG68]

I just wrapped up 20 some hours of adjusting my trunk lid. And it was like yours. Plus it was slightly cocked where the bottom of the right side was up against the quarter panel.
The specs call for a 0.16 gap on all three sides. I found a paint stirring stick from Home Depot that I measured as 0.15 thick with my micrometer so I cut off a small section and used that for my gap tool.

First I set the front gap to specs and pushed the lid to the left as far as I could within the hinge holes. This helped a bit but the gap on the left was still about twice that of the right side and the back of the lid was high.
Lowered the latch which helped some with the height, but it was still high and now it was hard to close the lid.
Elongated the left side hinge holes which helped some more., the right hinge bolt washers were up against the hinge so I couldn't move it left anymore, but I was making progress.

So I sacrificed some of the gap on the front to square the lid up. Loosened up the right hinge and pushed the lid back some. Front edge was now 0.16 on the left opening up a bit more on the right. This really helped square the lid and improved the gaps. But still high on both sides.
I didn't want to add shims and I had noticed that when closed, the left side had no give when I pushed down on the lid but when I pushed the right side down the left would go up. Hmm.
Shaved the left rubber bumper a bit and lowered the latch bracket some more. This lowered both sides and everything was beginning to look presentable.

So the gaps ended up as 0.16 - 0.18 across the front, 0.15 - 0.19 down the left side, and 0.20 - 0.16 down the right as measured by a mic. It's still not perfect and I think I can square it up a bit more. And I still have to play with the latch bracket a bit.
And speaking of the latch bracket, it was welded off to the right of center and at an angle which I think may be causing my difficulty in closing the lid

l.

[Scarebird]

yikes! that is a lot of work for something that should have taken 45 seconds at the factory.

I may cheat and use socket head screws with "D"ed washers as mine as yours butts up against the inside of the hinge.

[tjs72lemans]

I had the same issue. Got it as close as possible and called it good. I'm sure the factory wasn't as picky as we are!