Half a year ago I bought a second hand C5 Break, a 2.2 Hdi FAP Exclusive. These was the most expensive version, and most were sold with an autobox, but fortunately not the one I found. The car is from 2002 and had only done just over 90,000 kms.
I had it chiptuned (in the same way as my previous Xantia Hdi 110) and it now has about 165 BHP and 360 NM of torque, which makes it a quite convincing car on the motorways, and puts it in the same performance levels as the new twin turbo version. (for just 400 Euro).
It is a great car, very relaxing, but less frugal than the Xantia. Getting 1 liter every 15-16 km, means sedate driving, and using the power will give more like 1/13 to 1/14 km.