roof crack

Can anyone tell me whats going on here? Is this a layer of fiberglass that split?

 

Looks like Bondo, plastic body filler just spooned into a big dent, not the way it should be used BTW. Dig it out and see what you have. Probably a job for an experienced body and fender man.

 

Agree with chunk. Someone probably smacked it driving under one of those height markers at parking garages, or some other height restriction.
To do the repair job properly requires removing the headliner, which requires removing most of the trim inside, greatly increasing the labor.
Seems they elected to take a cheaper route. As chunk said, you'll likely need a pro. Good news is you can reduce the cost by stripping out the headliner before hand.

 

Removing the headliner from an AC is not hard, just tedious, take your time and give yourself plenty of time to take it slow.

 

It amazes me the lengths that people will go to just to do the job wrong. I once removed the headliner and pushed out a roof dent on a RCLB (not mine). The dent popped right out. The biggest pain was getting the headliner out. Not hard, but as Tundra2 said, "tedious".

 

Huh.

Obviously already answered correctly above; someone poorly used bondo to cover damage and the bondo has cracked because it wasn’t installed properly.

Looks like a tree branch might’ve fallen on the roof of the truck, or similar, and was filled with bondo, painted over. The bondo cracked (or water got under it) and water getting between bondo and the sheet metal is causing further damage.

The only real solve here is to rip out the bondo and see what you’re looking at for roof damage. You’ll need to treat the rust you’ll find (it may only be surface rust), take it down to bare metal, bondo properly, then repaint the roof.

 

Strong chance the stuff was applied too thick because rather than doing proper metal work and using it as a finishing touch to even everything out on properly repaired metal with some ripples they depended on the bondo to do most of the work.

A possible "get it ready for sale as quickly as possible" special after someone left the damage alone for most of the time they owned it. Slap it on, paint the roof, put a sign on it. Same sort of crap people pull with houses.