didn'T read the whole thread.
What I do when I find small size, annoying bubbles :
1. Scratch off the bubble with fingernails and finger scratch the rust to get an idea of the problem.
2. Pop off a piece of 320 grit sandpaper with this :
http://ezscrap.net/wp-content/uploads/2010/06/singleHolePunch.jpg
Glue that shit on the eraser tip of a pencil. Carefully sand the area then apply a drop of primer in the hole with a toothpick
3. Put a drop of color matched enamel paint over the primer with a toothpick.
4. Put a drop of clear over it and repeat until hole is filled.
The drops of paint look bubbly but they flatten up when they dry.
5. Pop off a piece of 1000 grit sandpaper with the punch and glue that shit on a pencil.
6. WET SANd.
7. Polish.
Fuck some bitches.
If the bubble is gnarly and sanding it will create too big an area for a small repair, I scratch off the rust dust and put a drop of rust converter in the pinhole.