RID Tiny Titans wave 4 is now out at American retail, some time after they showed up at American online stores (which already had wave 5 as well).

We missed wave 1 here, but Coles and Woolies seem to be stocking these a fair bit, as stores near me keep getting in new cases... so we might see wave 4 and 5 here soon too. (not that they are worth buying, at $5 each here)