Nothing as yet since I bought it, although there is an ominous rumbling sound coming from the front when cornering.
Trim seems a bit fragile too, although it is a Citroen, so what do you expect?
Good points - gives a smooth comfortable ride as long as it is not thrown into corners too hard, quite economical (just under 40mpg).
Bad points - awful gearchange, I don't know if this is a legacy from the last owner or a fault with all ZX's (probably the former as it was a woman!)
Engine needs to be worked hard to give decent acceleration and is noisy at 70mph. Like most special editions it is no more than a base spec model with jazzy seats and a sunroof!
All in all a sound, if boring family car.
A quick update, 3000 miles further on and has not cost me anything other than £35 for a small service, clutch adjustment has made the gearbox less clunky.
I am very impressed with the bodywork of the car, in fact on all ZX's, mine is seven years old and not a single bit of rust in sight, look at any Ford Escort the same age and you'll see rust along door bottoms and on the rear arches.
However, once it's paid for it is going the journey as it is just no fun at all to drive, perhaps I'll try a Saxo VTS next.