PontiacBonnevilleClub.com

2001 Bonneville. This is not something new, I know it's fairly common. I had the same problem with my 2001 Montana before it spread to the top surface and most of the paint peeled off. I just acquired this Bonneville and the problem is contained to the underside and I'd like to keep it that way. Should I scrape it off, clean all the corrosion underneath and seal it with something? Any suggestions?

If you are a DIY'er, just leave it alone. There is no way to contain it. It is aluminum oxide. Once it is there, it won't get any worse, it will just keep expanding. The only way to fix would be a complete strip down to bare metal, sand/media blast, and then seal prime and paint.