if you can, get one without a sun roof, they just leak
check the heaters work on all settings, i.e. 1-4
check the gear gaitor is secure
check the 3rd brake light works
check the hazard switch works
check for play in anti roll bar outer bushes
if its a 1.2 16v make sure you drive it, and that the engine runs fine with no fault lights or strange running, quite a few common'ish things can go on em inc coil pack / leads, map sensor, engine loom, mayo under the cap is fairly normal if it only does short runs which a lot of clio's will, people dont buy em to go the length of the country in every week