Hey Scoob....quick one, do you still have your OE rims? You can run them for a week to 100% confirm it's the steely set-up and not the rig. That's what I did when I was starting to question if it was my suspension set-up. Sorry I cant help out with a Perth recommendation. If you really get stuck, PM me and I'll give you my local guys number...think it was a beaurepairs (surprisingly) from memory...they may have a recommended "expert" over your way.
It’s definitely the Steelies. I drove to the tire shop down the freeway with the OEM rims on and she was smooth as, soon as I left with the new rims and hit the freeway it got the death wobbles right away.
I’ll send you a PM for those details, I need whatever help I can get as it’s making such a nice car such a disappointment to drive at the moment ☹️
In case anyone missed this , It can be caused if you get water in the tyres when a servo or tyre shop forgets to drain their air compressor tank.
I had this issue , the first tyre shop had no idea , tried to balance it for 25 minutes and gave up and put it back on the car anyway , i went to another tyre shop and he picked it straight away , there was about half a litre of water in the tyre