I just got done doing my tail panel, strange as it sounds, before I replaced the panel, everything lined up great, but since I have the OER qtr pal all is not good. I'll drop in a couple of picks of what I had to do to the tail panel to line everything up. I ended up taking my high speed cut off wheel and cutting a seam about 14 inches long (so when you bend the panel to fit it doesn't kink) then I tacked it back together slowly, once I was done, it fit rather well..Trying to remember how that went. For me, I had a few panels to replace, which included one of those small corner pieces that connect the valance panel to the quarter. Removing that probably gave me a little margin when test fitting. But, I feel like that actually fit pretty well. I have to take a look again in the day.
As for the edge of the tail panel...I pretty much started with trying to get the upper quarter edges and the pointed area at the sides to match up. Clamped behind the lights and then 4 bolts with washers in the bumper holes to help pull the tail panel into place while clamping and temporary metal screws where needed down toward the bottom edge. For me, the edges were actually slightly too tight. The rear right edge of the tail panel had to be cut and re-rolled a bit to match up between the quarters.
I'm actually going to do what jbloake recommended. I ordered an AMD panel and I am going to compare. While there are some areas I am happy with, I'm curious to see how that panel matches up.
you will have to grind away some of the edge o the tail panel to get everything to line up, but that's the nature of the taiwan replacement parts.
here are the pics.. Let me know if you have any questions..