External links
FAQs
- EdyJun's FAQ, DIY, Info, Tips and Help
 - s4biturbo.com FAQ
 - Neon01's FAQ
 - LI-S4's FAQ
 - General B5 A4/S4 FAQ
 - General Audi WIKI
 
Audi Parts
- Clair Parts
 - Euro Parts Direct
 - MileOne
 - Pure Motorsport
 - Shokan Coachworks
 - 1st VW Parts
 - VWParts
 - World Impex
 - Links to other sources
 
Tuners
- Achtuning
 - AMS
 - APR
 - Avalon
 - AWE
 - ECS
 - GIAC
 - MTM
 - NAV-Plus
 - STaSIS
 - Stratmosphere
 - TechReactions (EFU)
 - ToyGuy
 - UUC Motorwerks
 - Vast Performance
 
Other good starting points
Documents
- Me-motronic Engine Management from Amazon.com.uk (ISBN 3-934584-34-9)
 - The 2.7-litre V6 Biturbo Design and Function Self-study Programme 198
 - A New Approach to Functional and Software Structure for Engine Management Systems - BOSCH ME7
 - Audi approved oil chart (VW 502 00 and VW 505 01) Original from AoA
 - OBD fuel trim information - BMW specific but some applies to the S4 as well
 
Software
- WinOLS
 - ECUFix - Motronic checksum "corrector"
 - VAG-COM
 - Mark P's ECUx utilities page
 - Motronic map editor - Porsche specific, but still interesting
 - Bosch Motronic Reverse Engineering Project - Bare bones (but failed) attempt
 - OpenECU wiki - Subaru/Mitsubishi tuning software (Flasher, map editor, etc.)
 
Resources
- The definitive Audiworld DIY thread
 - AWD dynos
 - DIY MBC
 - Brake pad roundup
 - S4 1/4 Mile timeslips and videos
 - Nav retrofit information forum
 - Ticket Assassin - a MUST read
 - S4 Timeslips
 - Tire Rack
 - Speedvision World Challenge GT 2001 standings
 - Speedvision World Challenge GT 2002 standings
 
Audi Clubs
- Minnesota Audi Club - For Audi owners living in MN or bordering states. Events and private discussion forums.
 
- Socal Audi Club - For Audi owners living in southern California
 
S4 Owner Sites
- NogaroBlue.com - Chris Ostberg's (Verrückt) S4 site.
 - Mark P's site - Mark P's site for his Imola Avant.
 - MyAudis4.com - Flyboy's Audi S4 site.
 - nyet.org/cars - Nyet's (S4Wiki owner) site.
 - AndyWhittaker.com - Andy Whittaker's site.
 
Other Community Sites
Magazine Articles and Comparos
- Car and Driver "sport" shootout (7/1999)
 - Car and Driver "unfair fight" shootout (10/2001) (local mirror)
 - Car and Driver - B6 S4 vs E46 M3 vs C32 (5/2003)
 - Auto Express road test