Well another update
Got the bass transducers in on Friday but not the amp, but it didn't deter me from mounting them on the chassis.
Took one trip to Bunnings and one trip to my parents place to raid the shed for strips of wood and an old bicycle tire inner tube.
The wood helped mount it and the rubber helped make sure I wasn't going to get any metal vibrations if it wasn't tight enough.
Sunday I got too impatient so I bought an old amp off Gumtree for $100 and then hooked it all up.
For AC as the drivers are still in beta I get awesome engine noise, but not much else.
I tried LFS since that was also supported and that was very cool... impacts are great, gear changes feel cool, but as it' also has limited sensors I don't get the wheels sensation. I see iRacing does so I might have to download that and give it ago.
Overall it has some serious potential, but feels underdone... will report back if they improve AC support...