Cracked engine mount (that may have been already broken when I bought this ex-demonstrator model)
loose seat height adjuster
noisy auto-temperature-control sensor fan.
Very comfortable interior, although the ride is firmer than my previous BX 19GT. Japanese levels of reliability unlike my previous BX. and after 7 years and 92,000 kms the interior is lasting well. It still has the original exhaust system and I've only jut had to change the original battery. It uses no oil and there are no hydraulic fluid leaks.
A split rear seat would have been helpful and the boot is a useful size, but not large.
It has excellent performance and fuel consumption further improved by a Superchip modification. This car handles well, especially given the supple ride, although at the limit there is the usual front wheel drive understeer. The limit is high though.
I have an L reg Xantia 1.9 diesel and it is the most economical and comfortable car I have ever had. It did 135000 miles on the same clutch, and 152000 miles before we had to change the spheres. That job was easily done as a DIY project, although we needed help getting the old ones off. I love it!