What glue to stick polycarbonate and glass together?
Readily available products will include clear epoxies and marine grade silicone adhesives
Auto/Marine silicone sealant is typically rated to -40F, up to 350F and is quite clear between 2 pieces of glass, I do not know how the solvent will react with the PC in terms of changing the clarity of the surface. It dries like a high durometer rubber and can assist in noise/vibration damping from one surface to the next. These take at least a day to cure.
30-minute epoxies harden solid, but have a lower temp range, around -60F to 180F. They get HOT when they cure, which can lead to warping of certain plastics, but when bonded to glass this should not be a problem.
Optically clear lens adhesives are based on epoxy or acrylate and have a slightly more narrow range of temperatures, usally -40 to 150F. They are solvent free and are thus cured rapidly using ultraviolet light or heating (or both together). The lack of solvent should mean no change in surface clarity of the PC.