The catalyst broke in two after 60,000 km, which Peugeot seemed to find completely normal.
The exhaust broke after 80,000km.
The brake discs rusted onto the hub/ bearing assembly, and the rusting is so bad that the hubs will have to be replaced as they are out of true.
Rear brake assemblies (including drums) had to be replaced at 85000km due to corrosion.
Air bag sensor replaced after driving over a pothole apparently damaged it (despite the fact that this model of Partner has the beefed up suspension for "soft roading").
Engine appears to be very noisy (clattery), and in winter is very hard to start. This is not a glow plug problem, and neither the Peugeot or the Citroen garage can find the cause, so I will have to now try a diesel specialist. It could be injection related, which will surely turn out to be expensive..
The passenger foot-well fills with water when it rains hard. A search on the french forums confirms that this is not a rare problem, but unfortunately nobody (including Peugeot/ Citroen) seems to know the cause (and it's not just a dodgy seal - I've spent several hours trying to find where the water comes in, with no success).
The clock adjustment button stopped working after 70,000km (anyone who owned older Peugeots would more or less expect this...!).
The rear door catches are flimsy, and require considerable strength to operate them from inside the car. In general, the sliding door assembly is poorly built (the plastic coating on the slide rails has already peeled off, so they are now rusting).
The plastic neck of the filler tube for the fuel tank broke and was replaced, but despite this, plus a new seal, diesel still leaks from around the fuel cap when driving. The fuel cap is a stupid large plastic affair, which looks like it was made to break. Why they didn't put a simple filler cap with a cover I do not know!
The good points for this car are that it is cheap to buy, quite nice to drive (for a van type vehicle), has good fuel economy and there is a lot of space inside. Whilst it doesn't exactly belt along motorways, cruising at 140kmh is okay, although fuel economy diminishes rapidly above 130kmh.
The main bad points are that it is poorly built, seems to have a number of design flaws, and the apparent saving from the good fuel economy will be offset by the high maintenance costs. Also, it is very frustrating to have a vehicle that demands constant attention (and garage visits) due to problems.
On top of this is the poor service and high prices of the Peugeot garages (I have always found that Citroen are better and cheaper, and since this is basically a Berlingo, they seem happy to maintain it).
Lastly, to be a real utility vehicle, why oh why did Peugeot not make the rear seats easily removable? It requires a torx drive to get them out. Far from well thought out!
Overall, the choice for this style of vehicle is limited (the "car-van" type), but I would stay away from the French models (the Kangoo's problem's feature heavily on the French forums as well..), and perhaps opt for the VW Caddy if you can afford it.