When I was replacing the hatch seal on my Supra, I actually pulled some of the metal lip above the left taillight off with it.  Upon further inspection, I also noticed another rust hole almost right in the center on the rear.  I want to fix these without too much work.

I decided to try using some JB Weld to build back up the lip and fill the middle hole.  I will need to be able to the inside of the middle hole.  I lifted up the spare tire cover and removed the center panel from the back of the car.  I used an old paint stirrer to press against the material from underneath to ensure a good fill.  After the JB Weld had cured, I sanded them down, primered them and painted them.  The middle hole was fine, but the lip broke when I was putting the seal back on.  For right now I have just filled it with caulk.

1- No real difficulty, except for patience.  Make sure the material is good and cured before attempting any sanding.

1- As I said above, the JB Weld on the lip didn't hold when I put the pressure on it for the hatch seal.  Next time I  cut the lip away further, bend a piece of thin metal to match the curve, slide it up into the cut part of the lip, and use some glass filled body putty to fill it. 

Ok for one part, not too good for another.