Prod the S4's loud pedal, and chicks and geese and ducks better scurry. With apologies to Messieurs Rogers and Hammerstein, Audi's 4.2-liter V8-motivated surrey offers a soundtrack that borders on automotive pornography. Fortunately, with 340-horsepower and 302 lb-ft of twist routed to the ground via Quattro all-wheel-drive, it possesses the drivetrain bite to match its soulful bark.

While not apoplectically quick (0-60 mph in around 5.5 seconds), the S4 revealed itself as a prodigiously talented all-rounder over the course of our weeklong test. Many cars in its class impress with vulgar displays of power but struggle to put their gumption to the ground consistently and efficiently (Cadillac's CTS-V and Benz’s C55 AMG come to mind). Not so with the S4, which is the equivalent of a four-wheeled Sanford Sharpie pen, adhering faithfully to whatever surface passes 'neath its 18" Dunlop Sport SP Maxx tires. Whether the S4 is scribbling its signature on the interstate or autographing a set of undulating twisties in black silica, it leaves with a sound and fury signifying everything.

(Click through to the jump for on-and-off track driving impressions and 10 high-res photos!)

What's more, we're happy to report that Audi has finally figured out how to assemble a precise manual transmission. In the past, the four-ringed brand has been dogged by substandard DIY gearboxes. And while the short-throw six-speed unit in our Sprint Blue tester won't reorder the transmission universe, it makes for a pleasing tool by which to extract the best out of the Wards 10-Best Engine.

The clutch is similarly cooperative. Relatively light and commendably progressive, its linkage is easy to modulate. The fluidity of the S4's driveline and the heady racket of its 40-valver found us seeking out long tunnels with our windows down, if only to drop a cog and keep the engine within spitting distance of its 7,000 rpm redline. It's a sound that never gets old, even on mind-numbing straight-shot freeways. Critically, Audi has improved the S4's performance joneses for 2006 by employing a new Torsen center differential with a 60/40 rear-biased torque split on manual models. Tiptronic pilots will have to make do with a less sporting 50/50 setup, so consider this another reason to go for the self-swapper. Audi's subtle year-over-year change imbues the S4 with a more sporting character and allows for the occasional tail-out antic.

The Recaros we raved about in Day 3-4 reassuringly come good regardless of the task at hand-- be it a back-breaking interstate slog, or sine-wave of a b-road flog. Having an array of major controls at fingers' reach on the leather-wrapped wheel is a major plus, as is the multi-function information display nestled between the tach and speedo. With the exception of the occasionally cumbersome MMi, the S4's interior does right by the enthusiast, allowing drivers to concentrate on the task at hand-- righteously fast travel.

As one would suspect, Audi's reworked the suspension to cope with the S4's augmented drivetrain and sporting intentions. Ride height is abbreviated by 30 mm over the standard A4, with uprated shocks and anti-roll bars uprated front and rear. The amended quad-link front and trapezoidal-link rear setup works well, though matters can get a bit rough over pothole-strewn roads. Still, its rough-surface harshness is in-line/superior-to everything we've driven in class. Besides, the ride tradeoff quickly proves its worth when the tarmac gets interesting.

Brakes? Given the S4's top whack of 155 mph and tidal midrange torque that unwittingly invites extralegal speeds with frightening frequency, they'd better be good. And they are. The S4's anti-lock supervised ventilated discs are likewise governed by electronic brakeforce distribution (EBD) and traction control (TC). But given the inherently sticky nature of our S4's summer-biased Dunlops, we didn't regularly trigger Audi's electronic nanny state. When it did come into the picture, the (defeatable) Electronic Stability Control was reasonably progressive and didn't rudely cut engine output the way many systems often do.

All of which makes the S4's marshmallow-light helm such a tragedy. Audi's Servotronic speed-sensitive rack-and-pinion unit is over-boosted, plain and simple. In light of the S4's not-inconsiderable 3,800-pound heft, that the Audi's steering fails to adequately convey the gravity of the situation when thrown into a series of bends is problematic. It's a disconcerting omission for a vehicle otherwise supernaturally predisposed towards serpentine roads. Granted, all-wheel-drive is a recipe for traction, not necessarily for uncorrupted steering responses. Even still, we've had better. Audi engineers: "Once more... with feeling," please.

Obviously, the S4's a pedigreed back-road partner, but we couldn't help but wonder how Audi's compact sports sedan would measure up on a closed course. Fortunately, our new friends at Nelson Ledges were happy to indulge us. Almost by sheer happenstance, a drive around rural Northeastern Ohio took us to the door of the 2-mile roadcourse in Garrettsville. The well-respected racetrack plays host to everything from Spec Miata racing and Porsche Club functions to a number of motorcycle events and a 12-hour USERA enduro (the facility takes pride in being the birthplace of American 24-hour showroom stock races). With the racing season about three weeks away, we came upon a locked-up gate, but a quick conversation with the kind track custodian had us on the course in short order. As we hope to return soon to NL, we had to promise not to ball up the S4 into a decidedly unsmurfy paperweight. 

Nelson Ledges' surface could use some work, but the track remains very fast and makes for a fine test environment, particularly for an all-wheel-drive vehicle not easily unsettled (as proved the case with our S4). We hammered away at her for the bulk of the afternoon, coming away impressed. The S4's brakes are commendably fade-resistant, and the suspension and driveline worked to iron out irregularities without punishing our spinal cords. Better still, the clutch and gearbox combine with the big V8 to reward quick shifts with cosmic shove in short order, providing plenty of thrust around the course.

With the ESP's safety-net switched off, the S4's handling limits remained confidently benign, even where the previously-discussed over-assisted steering threatened to cloud the issue. Despite the fact that we'd never taken a lap on the track (okay, so we've timed a One Lap of America event or two here), the S4's behavior never truly veered towards the land of sweaty palms and four-letter words, despite speeds well into the triple-digits. After a long afternoon turning the 14-spoke alloys gunmetal black with brake dust, our throats (and the S4's gas tank) were parched.

One thing that did take a serious hit, naturally, is fuel economy. The S4 exhibits a positively Dionysian thirst both on-track and off. During a mix of admittedly spirited city and highway driving, we struggled mightily to crack the teens. We don't even want to discuss the V8's single-digit thirst at Nelson Ledges, lest Greenpeace televise a protest at the foot of our driveway. And never mind those soft-pedaling saps over at the EPA who quote 15/21 mpg city/highway. If you drive the S4 in a fashion even remotely consistent with its purpose and potential, expect all-highway mileage in the 13-16 mpg range, and perhaps 11-13 mpg when urban. As the S4 drinks exclusively from the high-octane pump, enthusiastic motoring comes at a high price.

Not least of which is the going rate on the S4 itself. Our evaluator was loaded with nearly $8k worth of options - everything from the oft-cited Premium package to the cold weather provisions, nav-system and carbon fiber trim. Oh, and $750 dollars worth of that Smurftastic paint. Figuring in gas-guzzler tax ($1,700) and destination ($720), would-be buyers will need to muster $56,620 in order to secure the services of this particular example (base S4s trade for a significantly more palatable $46,400). In truth, there are a handful of other all-wheel-drive four-doors that are just as quick for less coin (Subaru’s WRX STi and Dodge's Magnum R/T AWD come to mind), but we can’t think of one that incorporates the S4’s dynamic and sybaritic refinement. For those with thick bankbooks, Audi’s Surrey With a Fringe on Top might just be the slickest gig they’ll ever see.

Missed part of the S4's time in the Autoblog Garage? Get current with Day 1-2 and Day 3-4.

[Sources: Audi, NelsonLedges.com, NA-Motorsports.com, Stlyrics.com]