I recently bought a second hand DCi 100. Great little car, nippy around town and accelerates very well above normal motorway speeds.
Recently noticed it is a bit noisy if you push on from cold in the cold - not too bad this time of year during the day but early in the morning it is quite chilly (2-3am early), can't comment on what it will be like in the winter. In comparison to the latest Peugeot diesel engines fitted to similar size cars the Clio is exteremely quiet - I drove a 206 GTi Diesel (110bhp 170lbft) and that was very very noisey and intrusive whatever your style of driving! The Peugeot did pull harder at low revs (170lbft at 2000rpm vs 150lbft at 1900rpm) but lost all its pull past 4k whereas the Clio is still pulling but the red area starts at 4k on the Clio's counter, the red area starts 1k later on the Pug!
Whatever the noise level from the Clio tho I am still enjoying the satisfaction of getting 55mpg from quite short journeys