Rectangular headlight and tail light lenses

[Tgrzes]

Does anyone have any tips/tricks for making rectangular headlight and tail light lenses - materials, process, best glue to use, etc. I need a bunch, so buying pre-made is a last resort. I also need to make a few enclosed light bars. I’m not having any luck searching here or elsewhere on-line. I’ll try experimenting with material I have laying around, but was hoping for some advice. Thanks!