Nothing as yet. Although I have done a relatively low mileage and the car is still under warranty, Citroen has a reputation for unreliability, although I would argue that gremlins of the past have in the main been banished these days.
This car is sensational, and does very little wrong. As long as you're not looking for a sports saloon, you cannot fail to be impressed with the eerie smoothness, silence and refinement that is inherent in this spaceship of a car.
It has an Oleopneumatic suspension system called Hydractive III, and provides an inimitable ride quality that feels like you're floating on a bed of air. Speed humps are ironed out of the road, appearing to be absorbed into the car as you drive over them, rough road surfaces are eradicated and large undulations disappear as the magic suspension does its best to hide the shoddy roads beneath you.
Which makes it all the more tragic that in the UK, with its pockmarked tarmac, this car will hardly sell at all, despite being made for our roads.
It's no one trick pony either - the 2.7 V6 HDi engine is awesome for its wonderful torque, smoothness and relatively good fuel economy.
The interior is spacious, very comfortable and oh so stylish in a stunning avant garde way, which mirrors the exterior.
Those in know look longingly at what must be one of the most beautiful cars ever to be designed. It manages to be sporting, elegant, graceful, avant-garde and classical all it once, without being overtly flamboyant or kitsch. Those that ignore it are invariably either in a Mercedes or BMW, or otherwise generally blind to matters of aesthetics.
The C6 deserves to be a much better sales success that it has been hitherto in the UK. The French market is doubtless performing much better, and I hear it is proving quite popular in Germany.
Unfortunately, depreciation will prove to be a big problem for these lovely cars, which is a shame as they are almost up to the standard expected of a BMW or Audi in the same price-bracket, and much much more stylish and comfortable at it. Perhaps if the loss in value wouldn't be so heavy, more people would buy one - as it is you're all missing out on a spectacular car.
Just a small correction to your comments... C6 uses Hydractive 4 not 3/3+ which are available on C5s. Enjoy one of the best cars in the market nowadays.
The C6 employs Hydractive 3 Plus as does the 2008 C5. There is no Hydractive 4.