OK generally this car has been excellent; common problem is the driver's seat wears on the door side, due to getting in and out. Can't be helped.
Had to have the head gasket replaced at about 80+k, but that was my fault, forgot to check the water level on a return leg of a long journey. Dealer wanted £90 an hour plus parts to replace the head gasket, and quoted more than £900.
I found a specialist BMW garage who gave the car a service, MOT and replaced the head gasket for £600.
Another common problem is the wiring from the cabin through to the boot-lid; opening and closing this causes the wires in the loom to bend and eventually they snap internally. So rather than re-loom the car (I didn't even ask the price from the dealer), I inserted a new set of wiring from inside the boot-lid grommet to the rear wing grommet. This problem was found when it failed the MOT on a number plate light out.
The only other problem I've had is the remote for the central locking/alarm, doesn't always work. I don't know if they re-tune the remote or what, but at the moment my alarm isn't always on.
Overall opinion is I will buy another, but the 1600 engine is a little weak for the heavy car; next one will be a 318 or 320.
How can you call the 316 nippy, its sluggish and gets left behind by corsas, saxos, etc.
Add Nissan Micra 1.3 to that list!
Also add fiat punto 1.2 to that list.