Outer diameter is just one dimension. The height of the disc ("hat" height) determines where how far the disk sits back from the hub, aligning it with the caliper, and disc thickness when new is matched with different calipers. The AU Accord uses 28mm thick discs. These could possibly work with my calipers, but Honda specifies 25 mm for my car, so it could be that with new pads the caliper won't stretch wide enough. The pads used on the wagon are also slightly larger than the saloon.

Disc diameter tends to be matched with rim diameter. I think the 8th generation accord uses 320mm.