I've posted what happened before. Quick summary, I was working comission at a Shop. Myself and the other guys started having comebacks. Ended up with a bunch of comebacks, all suffering from filler bubbling/cracking/lifting. We used USC BC/CC (Basecoat/Clearcoat) filler which at the time was a premium filler and very popular. Turns out it wasn't just us having issues, former employer of mine who at that time was the President of a national auto body association said he was hearing from guys all over the country about this issue with BC/CC filler. He said USC was aware of this and was still producing batches of the filler with the issue. They didn't change the formula for months until they had used up all the raw materials.
I had dozens of cars that had issues. I worked for 6 weeks straight repairing them, not making any money. Eventually had to quit the job as the comebacks were still piling up. So did the other 2 body guys there. Because everyone quit the Owner of the Shop ended up closing it. All because of USC's faulty filler. They never honored their warranty nor acknowledged there was a problem. Once they changed the formula back to how it was prior the issue went away. They still sell BC/CC. I think it's called BC/CC Extra now. It cost me a lot of money and a job I liked. So no I will never use their products again.