Cox's Subaru vehicle had also destroyed a large goldfish pond and rose bushes established in the garden as a memorial by the previous owner. He killed 40 fish, damaged the house and left glass, fence posts and car wreckage strewn across the property.
Cox's persistence with his plea of not guilty had meant her insurance claim was yet to be finalised for the damage, which was repaired, and the tow truck driver who removed the car was still out of pocket for his work as well, she said.
"It's been a lot of bollocks quite frankly. As a victim I'm brassed off but more as a taxpayer " it's been the idiocy of the courts that has really frustrated me."
Reparations of about $4500 were being sought through the court to pay for the fence repair and the house painting that was also needed. The guilty plea would "at least" clear the way once reparations were paid, she said, to recover a $400 insurance claim excess amount she had paid.
"Here we are 18 months later and the insurance still hasn't been finalised and anyway, it doesn't cover the damage to the plants or the cost of landscaping. I'm out about $600 for the plants I haven't been able to replace and garden ornaments like the bird bath he broke, and I'm still fishing bits of his car out of the garden now," Ms Thompson said.
"He knows the system well and has gone through a line of legal aid lawyers and each time he fired a lawyer, it put things back again, and the judges have just seemed nothing other than pathetic, to be perfectly honest.
"He changed his plea at one point to say he wasn't driving; I mean he was pulled out of the driver's seat that night, obviously drunk and high, and there was a witness to say as much," she said.
"It's just incredible. He even started bleating he didn't have enough money to pay for a sleep expert. It's just crazy what it's cost us as taxpayers, just ridiculous. Even the police were struggling to understand why such an open and shut case has taken so long."
Ms Thompson believed Cox would be sentenced to community service and would likely struggle to quickly make good on any reparations ordered.
"I'm relieved he's finally pleaded guilty, I'm glad of that, but I don't believe it's the end of it. It will just be the start of another saga to try and get the money out of him. It's not over, not at all.
"You just get sick of being the victim all the time and being overlooked, while the criminal knows the system so well and walks away laughing.
"You try to do the right thing and play your part and you just get slammed in the face by the justice system, and all those things you believe in."