2009 A4 Avant trailer wiring

[Nick]

New question.  I have a 2009 Audi A4 Avant.  It may be an early build, 
it does not have LED tail lights.
Has anyone successfully added trailer light wiring to this particular 
model?   I don't think CURT  C56201 is the correct one, it is described 
as PWM converter.
I can figure out how to install a universal converter if I get word that 
it has been done safely.  (ie  Nothing blew up)
Nick


<http://www.etrailer.com/Custom-Fit-Vehicle-Wiring/Audi/A4/2009/C56201KIT.html?vehicleid=20091170055>