But the main motivator is probably the chassis rule regarding the diffuser. The rule states that the diffuser cannot be viewed beyond the body work when looked at in plan. So in order to mount a long diffuser, you must also extend the bodywork. A turbo motor only needs two. The lack of diffuser keeps us guessing even more.
T hat's more like it.
Gone are the odd chromed exhaust pipes. They allow for improved engine bay cooling, utilizing the useless area either side of the maximum width diffuser. The Audi R8C was revealed this week. Yes they both are longtail sports cars, but beyond that, they really share little visually. Mechanically they share the engine, transmission, brakes, and rear suspension.