the biggest thing here is making sure you have good LED's to make it all work... either find 12v led's and make it easy, or make sure you put the right amount of resistors on lower voltage led's so they don't fry as soon as you hook them up.

i actually bought about 4 sticks of acrylic rod 3' in length each. used a board and the bottom half of a pepsi can screwed to it for my diameter. turned the oven on and baked the rod on a cookie sheet for a few minutes, then took out and shaped around the can, using dowels i held it in place (was still kind of stiff), then put it back in for a little more baking time to help hold the shape better when it cooled off. the first set turned out just like chuck's pic, but after that i figured out how to make a complete circle then curl the two ends back so it ends up looking a little better. i think i'm going to make something similar, but this time make a shape that will fit the confines of my 240 taillights that's pretty much a straight bar of acrylic with an LED in each end and the cuts like in the instructions and see how it looks. all else fails i'll make a board full of the highest brightness led's i can find to put in there, but that's a lot of work