I have seen it both ways.... If it was me I would look in the junkyard and get the glass...

 

Here's an idea I've had bouncing around in my head. Replace the glass with plexi-glass and use the VHT paint people use on there tail lights. Or they also have spray on chrome now, the method is just like painting a car it's pretty cool. I saw a video of them doing it to a plastic darth vader helmet.

 

You should have factory tinted glass...

 

I do. I just like the idea if something less breakable and easier to tint.