I've seen a few variations of the rear cluster lights, I'm assuming this because of what light package your car has. If you got the LED/Xenon light then the rears will follow in the same manor.
There's a few popping up on ebay now and I want to get a retro fit xenon conversion in the near future. However on for the rears I've seen this:
Audi A3 S3 2013 Rear LED NEON Lights, Brand NEW, Genuine AUDI | eBay
Audi A3 S3 8V5 limousine 2013 Rear LED NEON Lights, Brand NEW, Genuine AUDI | eBay
They are both LED and they had a different style as to mine currently.
Why are their two variations? Is it because the 2nd one is from the A3 Saloon and its different?