Yeah I went hunting for Bosch but had the same problem with finding them in Canberra. Only place I didn't check was Auto Pro but no dice at Repco, Supercheap or Auto Barn.
I'm not too fussed though, good mate of mine has 2 cars with Trico on one and Bosch on the other (same reason he couldn't find them at the time of buying the second set) and said he can't tell the difference between them.
I'll let you know what they're like next time I get caught in the rain! I have some bugs on the front bar from my last road trip but GTR is mostly clean so I didn't wanna test today!!