The most serious issue was that it cracked a head gasket sometime before I got it - somewhere over 200,000ks? To be fair, this is a typical Holden problem in earlier models, and the previous owners gave the car hell and exceeded the weight limit towing, so I can't blame the car.
Fuel injectors failed.
Transmission become very clunky, (will need a reco).
Boot leaks (come to think of it, the whole car leaks a bit!)
Air-con doesn't work on 1 and 2 (but a delightful smell of fuel comes through.. safer to wind down the windows).
Rubber seals came off the doors.
The steering wheel partly fell off :) I believe it had a replacement steering wheel, which wasn't great quality evidently. The horn ended up as a little button in lower dash - not great if you're not left handed!
Fuel gage sticks.
Key has trouble opening boot.
Things needed rewiring (but wiring appeared very dodgy, so I'm sure this is attributed to poor job),
Radiator needed replacing.
Uses a little bit of oil (tired engine).
I love this car. It has had a very very very hard life (in animal form it would be at the SPCA), and despite this, it still runs!
The cracked head has been a real problem, and although it seems to be fixed, I'm too anxious to drive the car in case of overheating. If the car had been treated well, I am convinced it would run forever. Being a female, I love that the seats place me higher so I can see, and the interior is generally very roomy and comfortable - great for long journeys. This is a brilliant car to interrogate slow drivers in, although it should be noted the brakes do not stop it! I saw one person say they handle like shopping trolleys, and I thought this was a great and accurate comment!
My favourite thing would have to be the guts of this car - unlike Japanese imports, the Commodore will NEVER roll back on ANY hill - take your foot off the brake and she will pull forward, which I find extremely safe.
Fuel consumption.. hmm.. I never found it to be that bad, until I bought my 1.8L import. To be fair, the Commodore doesn't cost much to fill up, but it uses the fuel quickly around town (long distance she's disconcertingly economical). I ran it on 91, and was told it would be more economical on 96 or 98, so I ran it on 96 - big mistake! She ran well but I nearly cried at how much fuel it used - nearly an entire mark for short destination and back! So it was back to 91...
I wish I could have had this car after having been looked after, because it would have run like a dream. To her credit, she had so much guts you would never notice the head problem if you didn't check the water! I have absolutely no regrets in buying this car - it's a pity the modern imported cars aren't made like these super cars!