The range of tuning options available for the Audi RS6 makes one wonder if the standard car is a bit of a lemon.Conversely though, this is the German aftermarket tuning industry where even Porsche's GT comes under scrutiny for being too sanitised when it leaves the factory gates in Leipzig. Car (wagon) of the momentVast in scope the German domestic tuning industry might be, but the attention to engineering detail within it is meticulous. With regards to the RS6 Avant both Abt and MTM have already unleashed heavily modified versions of the car, unnerving AMG and M5 owners no end. Currently the RS6 is the design fad of the moment in German aftermarket tuning circles. Latest company to join the RS6 development circus is Siegfried Becker and Michael Bentler's B&B Automobiltechnik - and no, they don't have a bed and breakfast guesthouse adjacent to the premises.Based in Siegen-Birlenbach – what’s up with insane German tuning firms and small town locations? – B&B are chasing down MTM’s RS6, which is the current king of the hill with 517kW.Breaching the 500kW barrierThe RS6 engine is cooled by a special charge air cooler as part of the B&B conversion, with all engine management electronics thoroughly revised too. To keep the German Green party happy there are 100CPSI performance orientated catalytic converters which blend with the special performance exhaust system. Three states of tune are available, starting at 485kW, increasing incrementally to the mid-range package worth 500kW and topping out with the a bespoke 533kW package, besting both Abt and MTM’s offerings - naughty-naughty. Despite the RS6 hardly being a Lotus Elise in the mass stakes (2025kg), and factoring in the drag inducing all-wheel drive system, performance is still rather swift with a 0-100km/h time of 3.6 seconds and 320km/h top speed. Styling is left nearly untouched, rendering the B&B RS6 as a great q-car. Only the B&B's tailpipes in chrome, carbon or matte black finishes allude to something menacing being afoot. Audi fans will notice the 25mm ride height reduction too, aiming to improve high-speed stability. A range of attractive 20- and 21-inch alloy wheels are available too, with 30mm spacer sets to achieve a real autobahn storming look – in a station wagon no less. What’s the deal with the RS6?It would seem Audi have either built a massively reliable, under stressed 5-litre, V10 turbo engine in the standard car, or the German tuning firms are producing cars plainly in contravention of most emission control regulations. Alternatively some third force must be at work to account for the slew of power coming online in these RS6 conversions. Either way, 500kW RS6 station wagons are hardly sexy wheels, especially as most Ferrari owners will only get to see the bulbous rear-view. This brings us to that most peculiar German character trait, their very strange sense of humour. Nowhere better illustrated than a 533kW car with 1 660-litres of fold-down luggage space.