I've got the same problem with a 93 Civic HB
I'm past the bubbling stage and gone straight to penetration on both sides of the rear wheel wells. Bubbling started about 3 years ago, so Im afraid to know how much it has spread. The front looks great, but the back is totally infected...Bugs da heck out of me.
Been wanting to fix it a few times, but having no experience welding has kept me for taggling this project. Car is too old to put any money in, and I have grown to love it too much to sell it for like 500.
If anyone has pictures of DIY body work they've done to their car I would love to see it. Then maybe i get the courage to do it one day.
Living in Canada, its almost unavoidble; this situation.
Steve