If your holes are very tiny use JB weld on both sides. Be sure to work it in well. This is far mor superior to filler and you don't need to keep heating up the area. plus the JB weld can be used to smooth out the back side of the patch and make it unnoticeable. I did this in a couple spots on my GTO over 10 years ago and it still is just fine with no bubbles of any sort.
