EMpunker

I'd choose the Prestige just to have the Audi Dynamic Steering included in the Driver Assistance Package.

From sgrassojr's post on Audizine:

S4 w/o the driver assist option (a premium plus) has the following steering characteristics:
Comfort mode: Fixed ratio at 15.9:1 and speed sensitive high level of boost.
Auto mode: Fixed ratio at 15.9:1 and speed sensitive medium level of boost.
Dynamic mode: Fixed ratio at 15.9:1 and speed sensitive low level of boost.

Prestige S4 equipped with Driver Assist - Dynamic steering - only available on the Prestige:
Comfort mode: speed sensitive variable ratio from 9:1 to 18:1 with comfortable boost at highway speed. Suited for long highway journeys. Precise, but comfortable at highway speeds.
Auto mode: speed sensitive variable ratio from 9:1 to 18:1 with progressively less boost at higher speeds. Suited for daily driving. Precise and tight at higher speeds, precise and easy to maneuver at parking lot speeds.
Dynamic mode: fixed ratio at 14.3:1 with dynamic boost for most predictable dynamic driving. Suited for dynamic driving on the track or on mountain/canyon roads. 14.3:1 is a much more direct ratio than the standard steering which has a ratio of 15.9:1 at all times.

JSLevine05

When did dynamic steering become a Prestige only feature? My 2012 P+ came with it.

dave-t100

I just picked up my New 2015 S4 yesterday and it had the Dynamic Steering in it. Car is a Premium Plus with every option except 19" wheels, adaptive cruise control, Gloss Black Package and Adaptive Plus Xenon headlights.

Adam Lares

There's also carbon fiber intake and some other things wrapped with carbon fiber under the hood with the Prestige package. So I'm sure that also marks up the price another 1k. headlights would definitely be a $1,200 add on.