Anne contacted you on Radio 2UE some weeks back about her 2002 Astra with 108,836km on the clock with a piece off #2 piston and the workshop at Gateway Wollongong had had the car for 2 months. After 3 months they replaced the motor at considerable cost to Anne and returned the car without washing it and with greasy handprints all over the cover on the motor. Then 4 days later it broke down with the same symptoms as the original and this time they changed the catylactic converter and have said it's now 100%. I'd like to give you an update and hear another opinion of the situation.
This sounds to me like a complete disaster. A middle-of-the-road 2002 Astra is worth only about $4k as a private sale. The repairs probably cost more than the car, and certainly this is the case when you factor in the inconvenience of being without it for a quarter of a year.
If there's a chunk missing from the piston then the repair/replacement is absolutely appropriate. The timeframe isn't - that's excessive.
I would have scrapped the car and bought another one, or got a mechanic to replace the engine with a second-hand unit (un-reconditioned). In the case of scrapping it I would have cashed in the remaining rego and insurance, and then asked a few wreckers for a price to take it off your hands.
There are a couple of other salient lessons here. It says in your original message that you took the car to a Holden dealer for repair. This is a terrible mistake. Dealers are generally interested only in making money for themselves - so they probably didn't present you with the cheapest repair option appropriate to a car of that vintage.
Instead of the dealer, you need a good independent mechanic you can trust, for a car like that. You'll save heaps.
As for not washing the car - who cares? Wash it yourself. Dirty handprints - who cares? Wipe it down. Functioning car - important. Excessive repair time - important.
Did you physically see the damaged piston? Did they present you with the repair options? (Replace the engine, repair the engine, use a second-hand engine from a wrecker or a reconditioned engine?)
If you didn't ask to see the damaged part, that's a fail on your part. I would have asked to see the engine in the car with the head off and take a look at the cracked piston myself, to ensure they weren't bullshitting me.
As for the catalytic converter being the problem, that sounds like crap to me, too. I've never heard of a faulty catalytic converter shutting a car down. All catalytic converters do is help burn off some nasty exhaust gasses (into slightly less nasty ones). They are, however, expensive. It's hard to imagine how a fault in a catalytic converter could cause a breakdown
I'd call Fair Trading and voice your concerns - but proving those concerns will be hard. If the dealership said, "do this for $X" and you said "OK" you probably don't have any recourse. They're not required to present you with the cheapest option; nobody held a gun to your head to agree. You might also ring the Motor Traders Association and voice your concerns to them. They might offer you some valuable advocacy.
I'd stop using the Holden dealer in future for service and repair. Ask around for a trusted local mechanic.
If there's more information you'd like to share, feel free to use the comments section below, and I'll get back to you.