The resin they use is a polyester based resin. The smell will alwasy be there no matter the size of the part. The temperature is what will dictate how strong the smell is. The hotter the car is the stronger the smell will be. Bottom line is the part looks nice, smells bad and eventually warps.

 

The headliner or any parts that we make have no smell to them. Once the resin hardens there isn't an oder, there is if you take a heat gun and get it up to about 400 degrees. That and when you are making the part but after there is nothing.
As for the parts warping none of the parts that we have done over the past 6 years have ever warped from the heat of the interior of the car. I have done stress test's on engine covers that we make and even at 300 degrees only the clear coat that is on the part starts to aligator up. Meaning waves start to appear in the part.