For What it is worth,
The VX's & VXII's had a issue with tank units, where they would read 60 > 70 k's till empty, and you would run out if petrol,
I had a 2002 Berlina Wagon VXII and mentioned numerous times with the Dealer I was using at the time 'Booran Holden in Cheltenham' and they said they re-calibrated it,
Not sure what they re-calibrated, because I ran out of petrol twice after that,
So I took it back and with the service dockets and showed them what they said they did,
After a lengthy discussion, they offered to remove the tank and have a look at the Tank unit,
They rang and said it was faulty, and said I need a new unit,
I ended up having an argument with them over the same, and said,
"If you had of told me that in the first place, I would have just replaced it, but you charged me 4 times for re-calibration, and I still have the same issue, and have have probably paid for a new unit now, so I asked them to fix it correctly.
They said they would contact Holden and see what they can do,
They came back and said Holden will pay for the part under warranty, but I have to pay for the Labour,
My answer was, no way, after paying for 4 x calibrations and still the same fault,
I refused to buckle under pressure, I said the car can stay there till till the cows come home, until it is sorted out properly,
Holden Agreed to Pay for the Unit and the Labour, and that fixed t he on going fault,
However, I then traded the Car in 6 months later.