Legally it cannot be used everywhere, it is very expensive once it has been made fully coated for the durability cycle demanded of commercial use, usually 10 years.
The designer must now ask him or herself “What is my total cost versus what can be gained in mass reduction and design freedom?” The main drawback to a PC is weathering, resistance to scratch and scuffing. By the time you apply a hard coat, any potential savings derived from weight is now lost due increased piece price cost which can be as much as 4:1. There are infinite number ways that Design (Styling/Industrial Design) and engineering can and should work together upfront in the process. This can be used in the fixed vent window of, let’s say a Ferrari or framed sidelites for the XL1.
It saves weight, becomes a unique feature, like carbon fibre, but is unrealistic in normal production due to cost vs. value. Value still must be derived.
The Volkswagen XL1 uses polycarbonate windows to help save weight, just one of many distinguishing features
The Volkswagen hybrid concept, XL1 plug-in is one such vehicle that makes use of the innovative automotive lightweight solutions mentioned. The Volkswagen XL1 becomes the first vehicle to feature advanced plasma coating technology on two-component (2K) injection molded PC windows.