rust bubble - need advice

[ithaca]

Hi All,

20170617_193013_sm.jpg

I was washing my car and noticed what appears to be a rust bubble (see arrow pointing to it in the pic). Any chance this would be covered by BMW warranty? If not, should I use a rotary tool to get rid of the rust, fill in w/bondo and paint?

Thanks in advance,
RM

[TonyAngel]

Those look like they rusted from the inside out. My guess would be that you are way beyond using a rotary tool. Is your car under the factory warranty? I have to ask because I have no idea how long a factory warranty lasts.

[White94RX]

Not going to be covered under warranty.

[slides]

probably cheaper and easiest to buy a used trunk if you can find it.

[georgebuhr]

First I'd suggest looking inside the trunk to see if there is signs of rust on the inside. If not, its a lot of work to paint the lid for that small of a spot. I don't know if you can still buy them, but they actually make a small sanding pen with a small tip with abrasive on it. I would sand the small bubble off then get some touch up paint to go over it so it doesn't keep rusting. In fact if you got base color and some clear, you could then build the spot up, then block it flat with some 2000 grit, a little polishing and you will never know its there. This will only work if you can keep the repair area very small. If the rust spot is bigger underneath than what your picture shows, then you may be better off to paint it.