The tail light for the S4 GT and GTS models comes in two versions, an EU version and A US version., It is hard to immediately spot the difference.
The US style does not have a fog light (92863148401/02) where the EU version
(92863148400) with E1 label has a fog light and reflector. The missing reflector
in the US version makes it look dark red where the EU style looks brighter red.
USA version 928 631 484 02
EU version 928 631 484 00