apart from polycarbonate being much cheaper than cf and little heavier is difference structurally, strength wise, expansion rates in varied temperatures that different ?

basically is polycarbonate/perspex (not sure what grade etc yet as i will look into this later) more than suitable a material to use as sunroof plug ?

i will be plugging my sunroof at some point in future to eliminate weight but hoping i can find cheaper option than buying $400 + shipping cf kit, have nothing against them but cant justify that kinda money in trying to lose weight from car

i know theres other options but need to consider budget and dont want aluminium sheet just riveted on and sealed as car will be used on road