Factory build sheet

2021 Audi S4 Quattro Prestige

Build WAUC4BF4-M · 3L 6cyl · All-wheel drive · Sedan

VIN positions 1 through 8 read WAUC4BF4 and position 10 reads M. Those nine characters define this build. Position 9 and positions 11 through 17 differ on every car.

Every S4 whose VIN starts WAUC4BF4 and carries M in position 10 left the plant with the same engine, transmission, drivetrain and equipment listed below. We know of 23 of them.

  • Decoded Jul 7, 2026
  • 23 known VINs
  • 2 listed for sale now

Factory specification

As filed by Audi with NHTSA for this build. Fields the filing does not record are left out entirely — a missing row means no recorded value, not a missing feature.

Engine

Displacement
3 L
Cylinders
6
Engine model
349 hp 3l v6
Horsepower
349 hp
Fuel type
Gasoline

Drivetrain

Drive type
All-wheel drive
Transmission
Automatic
Forward speeds
8

Body & chassis

Body class
Sedan/Saloon
NHTSA body type
PASSENGER CAR
Doors
4
Seats
5
Seat rows
2
Manufacturer
AUDI AG

Weight rating

GVWR class
Class 1
GVWR
6,000 lb or less

Gross vehicle weight rating is the loaded ceiling set by the manufacturer, not the car's own weight.

Driver assistance, as built

  • Crash imminent braking Standard
  • Blind spot warning Standard

Systems the filing does not record are not listed above. Check the window sticker of the exact car before you rely on any single feature.

What this build asks today

Asking prices of live dealer listings decoded to this exact configuration — narrower than the trim-level figure, because every car counted here shares the same engine, transmission and drivetrain.

$33,139 median asking price · 5 listings · as of Aug 30, 2026

Too few listings to publish a price range — with 5 cars on the market, the cheapest and the dearest are single cars, not a spread. The median above is what they ask in the middle.

Compare every 2021 S4 trim and its price →

The same build, other model years

Audi used the VIN pattern WAUC4BF4 for 2 model years. Nothing but the year changes between these pages, so the price gap between them is depreciation on an identical car.

How this VIN pattern is read

A 17-character VIN carries two kinds of information: what was built, and which one it is. This page is the first kind — the nine highlighted positions.

Positions Characters What they encode
1–3 WAU AUDI AG · World manufacturer identifier
4–8 C4BF4 Model, body style, engine and restraint system
9 × Check digit — computed per vehicle, not part of the build
10 M Model year — 2021
11 × Assembly plant
12–17 ×××××× Production sequence number, unique to each vehicle

NHTSA safety ratings

Crash-test results are published per model year and body style, so they cover the 2021 Audi S4 as a whole rather than this build alone.

Rollover

★★★★★ 5 / 5

4 recall campaigns are recorded for the 2021 S4. Recalls are issued per VIN range — check the VIN of the car you are looking at, not the model.

23 vehicles carry this build

Every VIN we have decoded to WAUC4BF4-M shares the specification above.

  • 23 Known VINs
  • 2 Listed for sale now
  • 5 Priced listings
  • $33,139 Median asking

Neighboring configurations

Other factory configurations of the S4, each with its own build sheet. The set is fixed by the VIN patterns themselves, so it does not shuffle as prices or inventory move.

Keep going

Where this data comes from

Specification fields are decoded from the manufacturer's filings in the NHTSA vPIC database, keyed on VIN positions 1–8 and 10. We publish the filed values as they stand and leave out anything the filing does not record.

Prices are asking prices from 5 live dealer listings decoded to this build , last updated August 30, 2026 . They are what sellers ask, not what buyers paid.

Vehicle counts come from the 23 VINs of this build we have seen in dealer inventory. They are a sample of the road population, not a production figure.