i think the problem u have is 99% of imports are sold as seen.
if it went through rego etc and pits then its there fault they missed its a cut n shut, which aint hard as u can see the joins under neath, so its not the companies fault and they can deny they knew anything about it etc etc
so the only place u have to stand is probably the place that gave it a license in wa to be on the road, unless u had an inspection on it etc but at the end of the day they just have to say they dont kno what ur talking about, as u bought the car exactly how they sold it.
thats how i understand it,
sorry m8