Like a B-2 stealth bomber, Audi's RS4 has always possessed the ability to travel at high speed with the minimum of unwanted attention, whilst carrying a heavy payload. And although the intentions of most RS4 drivers are usually good deal more peaceful, the ability to outrun almost anything else when the need arises is a key attribute.
The ability to do just that has made successive generations of Audi's supercar-rivalling five-door one of the most desirable fast estates on earth. And just like its Northrop Grumman alter ego, the investment required to make the RS4 go that quick is substantial - which is in turn reflected in the asking price.
Fortunately, the RS4 has been extensively updated over the last 18 years, and as each generation has aged it has also depreciated. So the B5 and B7 cars can now be bought for less than £20,000, although the original B5 is now starting to appreciate.
Owning an RS4 does require you to make some compromises in terms of running costs but - when the mood takes you - you can savour the kind of performance normally reserved for only the very fastest of sports cars. Whilst the rest of the time you can happily travel about almost incognito.
In the beginning of course, Audi and Porsche created the legendary 1994 RS2 - a 315hp estate car with a five-cylinder turbocharged engine that broke the mould. And the RS2's successors have carried that mantle all the way through to the present, boasting front-mounted, longitudinal engines and Audi's trademark Quattro four-wheel-drive transmission.
The original 1999 B5 bi-turbo V6 RS4 was produced as a five-door Avant only and was reasonably well received, but Audi decided not to produce a B6-based RS4 to replace it. A second-generation V8 B7 RS4 did finally arrive in 2006 - initially produced as a four-door saloon, with the Avant following a short while later. A two-door, four-seat Cabriolet was also eventually added. The third-generation B8 RS4 arrived in 2012 - this time again in Avant form only - and very latest fourth-generation B9 RS4 Avant will arrive later this year.
Soon to be four generations then, but which one makes the best buy right now? Will all RS4s become future classics? And which incarnation makes the best starting point for further modifications? These are all questions we're aiming to answer.
Many thanks to Revotechnik, MRC Tuning, RS246 forum, Audi Sport and Glass's Guide for their help with this feature
