nothing major, accident damage is the main one, check where the rear arches are bonded onto the original clio metal work (under the rear window and the rear 1/4, and on th insides of the doors)
stone chips on the front bumper is normal, they all do it
the clips holding the under bonet tray in will have probably gone rusty, normal
scrapes on the wheels, these cars are very sensitive to "female driving technique"
gearbox should be tight and notchy, and no funny noises when driving in 1st gear on full lock (diffs were shite on the mk1's)
mechanically the clutch is the weakest point, check for service history, it will have the wrong oil in it more than likley! (renault dealerships)
tyres should be 205/40 18 michelin Pilot sport 2 front
and 245/45 (i think maybe 245/40, can't remember) rear (£700 for a new set remember!)
accident damage is the main thing to look for