Advice needed: Cracks forming on Rear Body Panel

[talibraza101]

Thanks for the input everyone. After using a weaker magnet I can definitely tell there is a layer of bondo behind those cracks that are forming. Definitely a bummer knowing there may be rust pockets lying under the paint. I do like @Chamba ’s idea on waiting until the bondo pops off and then having a clearer picture on where to emphasize repairs when its time for bodywork.

 

[brian]

You really need to open it now. Waiting will allow moisture to be trapped therefore accelerating rust, that's already there.

 

[Wasatch Jay]

My understanding is cracks in bondo could have different causation with two of the most common being inadequate surface preparation, and bondo that was applied too thickly. At this point you really don’t know what caused the cracks, or what lies beneath….

I realize there is a strong temptation to investigate, but here’s the thing: Paint and body work is not cheap, and that's especially true when it’s done right.

This rabbit hole could be long and expensive. How deep are your pockets (and I ask that not to be rude, but rather as someone whose projects NEVER come in on budget)?

Are you really sure you want to open this can of worms?