Philia_Bear;68310 wroteIf in NSW
302 conversion == self certify under new laws
320 conversion == Engineer certification required
This is definitely the situation now if you're in NSW, though the swap to the 302mm rotors wont require you declare it or do anything at all.
The 280mm to 302mm swap, simply requires the replacement caliper hanger (currently NLA, but should be available again to purchase in April apparently), the larger rotor and the longer brake line.
No one, other than volvo-enthusiasts will really know which cars had 280mm brakes and which had 302mm brakes.
The 320mm conversion, much like HSV, FPV, Subaru and many, many others using big brakes on higher-spec models requires an adaptor between the upright or hub and the mounting ears of the caliper or the caliper hanger (typical in a sliding caliper design).
This is interesting for the aftermarket or even optional dealer-fit or factory-fit upgraded brake packages as they wont specifically have a certification for the upgrade.
The 320mm calipers can be purchased with Volvo branding (used on S40/V50T5 AWD as standard) or with FoMoCo branding (on LS-LV Focus XR5).
I think, in NSW, you'd be hard done to have anyone even pick that the brakes weren't factory fitted - they're a rather unassuming looking caliper and if you find yourself using volvo branded ones, and the fact that the adaptors are not obvious, you'd be very unlucky to run into an 'that hasn't been engineered, mate' discussion with police or anyone else (they may be more focused on pod filters and blow-off-valves instead).
If you have specific questions about doing it, just let me know and I can answer them for you.
