Sysiek is right .... best method and cheap. Dont even bother buying lexan. Use a used soda bottle. Heat it with a heat gun , and pull down over wingtip. Use a cloth to press down over it so you don't burn your hand. This is less hassle than vacuum forming. We have a vacuum former set up in the shop, and don't eve bother with it for things like tip lights, unless we need to do a run of several copies
all best,
Voy