I don’t feature much based on tuners, as their work are usually done on existing (type approved) car models.

As Motoren Technik-Mayer – more commonly known as MTM – decided to piece an enhancement in what seems as their own type approved model, things get more worthy of being mentioned.

Its background

At end of 1993, Mayer starter working with a 1993 Audi S4 as a customer commissioning. The task at hand; to create a spectacular Avant capable of 300 km/h.

MTM is well-known for their proper performance upgrades for a lot of VAGs, but this time it was not a matter of “just another motor build” – the car is also enhanced in terms of the aesthetics.

Transforming the S4 chassis into wide-body

That resulted in this kevlar wide-body Audi S4, executed by Schneider Motorsport. Hidden under the wide arches and ensuring an equal rolling radius, is a set of BBS center-lock wheels from the Bugatti EB110. They are a whooping 10 & 13J18 feat. staggering 245/40 tires up front, and 325/30 at the rear – quite extreme back in the mid 90s!

How wide it is, in the hands of the first owner (Hamburg).

Even if the arches are perfectly matching the design of the “soap bar”-design Audi, other changes are apparent too. Side mirrors are of a cup-inspired design and is hugging the A-pillars, simply to reduce drag. The rear bumper features a tucked away diffusor section for dual exhaust, while the rest of the car is very subtle and true to the original design.

MTM RS6 cup style-mirrors

The exception may be the front spoiler though, and a rather well-ventilating one. To be honest, I find it noticeable how this design is seen on the A!vantgarde styling that was offered for 1st gen. Audi A4 1995 upwards.

Deep breaths, deep position…with carbon-lip

What it was kitted with

Going back to the core of the MTM business, this build is also about MTM’s ability to tweak the performeance. The well-known 20V has been mated to an upgraded package around a KKK K27/28 hybrid, put on a Sport Quattro manifold, offering 2.0 BAR of boost.

This 420 hp package is far from extreme by today’s standards, and seemingly a known receipt at MTM from the heydays.

Being so lucky to get a ride in this on a track day in 2004, I found the power-band really linear and highly drive-able. Backed up by a rather noticeable level of grip, this barge really made it through the bendy bits just fine.

Seeing the motor being suited to the project, achieving the desired top-speed was only possible from a re-gearing by a lengthened top gear – a 2.5 TDI sourced item for 305 km/h. Also the fuel tank was heavily increased into what seems 250 L, so this makes it quite the Autobahn-missile.

RS6 or S4 RS?

There is an old saying behind this S4, that MTM were the first to type approve “RS6” as a model name, and that Audi had to purchase the legal rights for it when the first generation RS6 were developed. I have never seen any evidence of this claim though.

Hans Dahlbäck (RIP) once presented this car for the Swedish car magazine Bilsport, where it titled as Audi S4 RS. In a way this suits the car historically, mind you the build was initiated late 1993 on a same-year Audi S4.

Aside of it’s S4 origin, MTM removed the S4 badges and put on both the MTM-logo and a Porsche RS-badge. Seeing how the import to Norway has been handled, the car is officially Audi MTM-RS6 by the paperwork.

1st owner sported personal ‘RS6’ plates

Even though the change from S4 to S6 is somewhat confusing for those more familiar with the newer Audi models’ A-series designations, such changes were basically a facelifting of the Typ 4A.

When the first owner in Norway, Jørn, got it, the MTM RS6 was given the current S6 facelifting through a new bonnet and a heckblende (reflex-bar). With all the curves of the wide-body and smooth bumpers, I think it is a change that works out very well.

MTM RS on large three-split BBSes.

For the record, Jørn also used a set of BBS RS on it, and I remember the car sporting special instruments with MTM-logo and ranging up to 320 km/h.

The RS as of today

Luckily, this unique build has recently been at MTM undergoing an extensive restoration for the 2022 season.

And I say unique, as there exists a second car too. Built in 1997, for a Czech who fell in love with the original. Overall, only 3 sets of widebody kits were fabricated (but the moulds are now sold too).