Faults:
An engine mount broke which resulted in a fair amount of vibration, but was an easy fix.
Starter motor replaced.
Leaks oil.
Cracked exhaust manifold - replaced.
Minor electrical niggles - the electrics were always a weak point of the 12. Little things like the dash light brightness adjuster crapping itself, the cigarette lighter does not work when the headlights are on, dash signals like the high beam indicator crap themselves, and if you can find a 12 with a working rear window demister it's a blue-eyed miracle. But the major things still work well.
Rust appearing at corners of doors - but to be fair it has been exclusively outside for the past year and a half.
General Comments:
This car was something of a gamble. It was bought to replace the 1987 BMW 325 which was a great car, but moved on before serious maintenance was required. Its job was to last around 18 months.
It has succeeded brilliantly. It has driven about 92000 km in that time, mostly at 70mph/110kmh on the freeway. It has required a few things to be fixed along the way, but mostly minor things. The beauty of these cars is because they are so basic, you can service them yourself, or if you can't, they usually cost no more than AU $200 (about 80 quid) to get done.
These cars do have their quirks and you need to be something of an enthusiast to put up with their foibles on a daily basis, but I don't know what other 30 year old car (outside of a Corolla) would put up with this kind of use. The motor could run out of oil and water and it would still go.
The seats put many new cars to shame in terms of comfort.
The narrow pillars and high seating position give great visibility with very few blind spots.
Cabin ventilation is pretty weak and it takes a while to clear the windscreen on a cold morning.
This car has the later, bigger 1.4 L engine fitted, as well as the 4 speed transmission from an R17 so it takes the edge off at freeway speed, but it still does 3600 rpm at 110. The economy is not particularly special (8-9 L/100km) and performance... OK with driver only, a bit sad with 3 or 4 people. The engines strengths are at the top end and it will continue to accelerate up hills once it's at 4000 rpm and beyond. However a few hundred cc's and a 5th gear would have helped tremendously.