My daughter has an early 2007 1.2. Front suspension strut tops are prone to failure (turn from lock to lock and you should feel a "knocking" noise, confirmed by putting a hand on each front spring while the steering is being turned. Check for a service history showing the cam belt has been changed. Electric power steering is prone to failure. Hard to detect when checking the car. It usually either works or it doesn't. You sometimes get a sort of "chattering" sensation through the steering wheel when you turn it slowly. Front anti roll bar droplinks are also common (but very easy to change).
Rear brake adjusters always seize. Handbrake cables can fail. Clutch slave cylinders sometimes leak. Clutches tend to bite "on the floor" and sometimes don't release properly.
Electrical problems are by far the biggest. Main battery earth straps can fail (either at the body or on the gearbox under the clutch slave cylinder). Sometimes water can get into the main fusebox if the lid hasn't been fitted properly. Look for condensation under the lid. The wires from the frotn doors to the A pillars tend to fatigue and snap (check all doors centrally lock and both front windows work).
The steel coolant pipe going across the front of the engine behind the catalyst can rust through, and the thermostat housing has some very weak plastic spouts on it.
