[sirajali05]

I noticed a small cut/crack on my roof, only a few millimeters long. It's bizarre as it seems to be kind of outward (see the attached pictures). I have no idea what could cause this sort of thing. I would apply some touch up paint and clear coat to "seal" it, but I am worried about moisture already getting in there and causing rust or corrosion.

Has anyone ever had anything like this happen to their car? I will check with my local dealer to see if it's covered under the 12 year rust and corrosion warranty, but I am not hopeful.

The car is a CPO 2017 340i. Thanks!

[Desertnate]

In both pictures there seems to be an irregular shaped area of a slightly different color around the spot where the paint is cracked. In the second pictures it appears to be slightly raised, just not as high as the cracked area. Is that what's going on, or an illusion from the lighting when the picture was taken?

I'm wondering if you have some rusting going on below the paint which is causing it to bubble and what you see if the first sign of the rust breaking through. The only other thing I could think of is a PDR gone horribly wrong.

[sirajali05]

Originally Posted by Desertnate

In both pictures there seems to be an irregular shaped area of a slightly different color around the spot where the paint is cracked. In the second pictures it appears to be slightly raised, just not as high as the cracked area. Is that what's going on, or an illusion from the lighting when the picture was taken?

I'm wondering if you have some rusting going on below the paint which is causing it to bubble and what you see if the first sign of the rust breaking through. The only other thing I could think of is a PDR gone horribly wrong.

Good eye! The different color is due to me wiping the area with the crack, so the surrounding area is dirtier/dustier. And it is slightly raised where the crack is, but the wiped/different color area isn't raised until it gets near the crack. I was also thinking along the same lines, and the bubbling protruded enough to start cracking. I am wondering how it could have rusted to begin with, though.

[muniz_ri]

My guess is that the roof may have been previously repaired and painted. It will require sanding, priming, and repainting to fix that. It would be possible to diy but having a pro do it would be best.

[bellguy]

Looks like at some point it's had rock chip damage that was left untreated for a while, then as rust formed it was touched up before sale but done badly, moisture and the rust came through again splitting the paint, you can clearly see an area around the split that is slightly lower, that is the original touch up area.
If job was done correctly in the first place this crap wouldn't happen