Now that the M3s have been split out into two sections, E46 and E92, I cannot find a way of performing an advanced search for the E46 as the 'M3' option only seems to search the E92 section.
We are halfway though the split at the moment, so there might be a little bit of weirdness occurring.
The best option if you are having problems at the moment is to go into the E46 M3 category and click 'Filter' at the top. This should get round the problem!