So if they are acrylic rods with LED's on each end, then each tube is custom made as they are not flexible. Though from the picture, they do not seem like acrylic rods as they require strong LED's at each end of the tube to provide an even distribution of light. The mounting of LED's may be a problem with limited space following the silver trim of the headlight. Using one LED unit in a acrylic or silicone rod would result in hotspot as well. The line of light in the picture posted looks very evenly distributed. Can you clarify on what was used?
Audi and BMW are starting to use polycarbonate rods with frosting and slits on the rod lens themselves to produce the perfect evenness of light. Not to mention their LED units are designed by electrical engineering firms like Osram. They are almost unobtainable for any general market.
To have flexibility for general use, SMD LED's on flexible copper PCB in a silicone package for even light distribution may be easier. I know Morimoto launched a COB (chips on board) LED strip with silicone top for flexibility last year. I'm sure plenty from China and Taiwan have replicated it by now.
None the less, this is quite interesting. When I changed my turn signals to switchback LED's, the white reflection off the silver trim gave me a similar idea (see attached image). You can see how the curve of the trim is quite beautiful when there is light following it. Unfortunately, I don't want to ruin a tech package pair of headlights by opening them up and slapping on a strip of LED's and render them practically useless. Many have tried to replicate the brightness and evenness of new Audi's, BMW's, and even Caddy's to have them effectively use as DRL's, but all have failed.