These plans have apparently been scrapped. A lack of safety of nickel-metal hydride batteries is cited as the reason for the cancellation. Apparently a senior Audi official said "Audi won’t produce a petrol-electric hybrid until we can make nickel metal hydride batteries safer in crash situations, and hybrid technology more efficient overall. Until then we will concentrate on producing more efficient diesel engines and aluminum chassis.”
This reasoning appears suspicious considering how long nickel-metal hydride batteries have been in hybrid cars. After all, over a million Priuses have hit the roads using these since the car was first introduced 8 years ago.
Imagine what Audi thinks of lithium-ion batteries.