Colour - inconspicuous ; so Phantom Black, Daytona Grey or Mugello Blue (if only...) preferred
Extras - FBSW and buckets essential, satnav and bluetooth nice to have
Condition/SH - is everything, mileage negotiable up to about 80k
And I can't quite stretch to pekingprawn's mint example, the price must start with a one.
As an aside, as a southern softie I'm intrigued to see that most RS4s seem to have migrated North.

Wilts_RS4