Holden Captiva: Lemon

My husband and I purchased a new Holden Captiva diesel in 2012. Within the first few weeks it had to be towed after warning lights came on and it stopped on the side of the road. Throughout the three years we've owned it it has had one problem after another. The past year the faults included intermittent problems with the centre dash lights going off, the power faltering for a few seconds at a time after the warning lights come on, and the car sometimes accelerating by itself. The dealer has kept the car for weeks and months at a time as they searched for each problem and replaced many parts, and each time I was hopeful it had been fixed. They acknowledge the problems and I have a huge stack of paperwork from them and also correspondence from Holden Customer Care. I approached Holden late last year to say I'd had enough and requested that they purchase the car back from me as a secondhand car, for the amount still outstanding on the loan (around $15,000), plus a further $6000 to cover the original deposit we paid. I received the car back last week after they'd had it for three months. They'd attached a data logger to the car, which showed no errors. Throughout the time I've had it the car has had intermittent faults, sometimes it would have no faults for a few months, but sometimes have multiple faults in one week, so I'm not confident the car is fixed. Holden has offered store vouchers as compensation over the years, and have now offered for us to purchase a new Holden at a heavily discounted price. This would mean we would still need to pay out the existing loan as well as take out a loan for a new car, only to be left with another Holden, a brand we no longer trust. It is so frustrating. After speaking to Consumer Affairs, our only other option would be to go to VCAT. Would you know if I would be likely to have any success if I went to VCAT?