If it's polyurethane then folded makes sense. Makes for a much smaller package. I had a lip shipped folded for my IS300 and it had no issues with breaking/cracking/having a bend in the middle.

 

my lip is being painted at the moment. How did the paint hold up on your poly lip? They seem to been super flexible that I fear the paint may flake or crack

 

Here's the finished product. Car is dirty from a rainy day here, excuse the picture.
I like the way it looks. May or may not get an M bumper come the spring. Not sure yet.

Still have my carbon fiber H type lip up for sale if anyone is interested in performing magic to make it fit. I will let it go for cheap just PM me.

 

Mine held up fine. Then again I haven't seen my IS in about 2 years since she's been sitting in storage haha. But my M5 front bumper is polyurethane as well, paint held up extremely well actually. It's probably more dependent on the body shop and the work the person put into the bumper than the material itself.