I have a problem. Car was stripped down to metal and repainted 2 years ago, never seen the rain and only a couple washes. There were no signs of rust at the body shop. On both sides, at the base of the sail panel I have bubbling. It is not a paint drop because it is growing. What can I do to stop and repair this?

Did the car originally have vinyl on the sails? If so, I had the same thing happen where the hole went through the body for the trim piece. The body shop did not treat the holes the welded up and I got bubbling at each spot. Sadly, the shop wouldn't stand behind their work and I had to pay for the repairs. Part of the fix was to remove all the rust from the under side of the fender.

Unfortunatly, these cars rust from the inside out. The foam inside the sail panel is to blame. The only way to fix is to cut out the metal, cut out the foam, weld in new metal and repaint.

Very rarely, if ever are rust bubbles a simple fix. Once the metal underneath has gotten to the point of letting the paint blister, it's usually an involved repair.

I had a six years ago and after I cleaned all the years of dirt from under the fenders a bubble popped up in the same place... The dirt was keeping air from the rust and once cleaned it started growing. Cut it out and had metal grafted in ....fixed worked for years.
I always laugh ( scoff I guess) when a car is advertised as "no rust" but a couple of bubbles .......Right
Good luck but bite the bullet now or it just grows like cancer .