In the US, the E36 M3 ran from '95-'99, the E46 M3 from '01-present. So for your purposes, you're looking at '98 and '99 cars. You may want to consider expanding your search to include all '95-'99 cars. '95's have the distinct advantge of being more resonsive to mods since they are OBD-I. '96-'99 are OBD-II.