some will be missing because that particular model never made it into production maybe, i.e
E36 (3 series), E37 (Z3?) E38 (never passed design stage?), then E39 (5 series) then a few more that never got past design stage until E46 (previous 3 series), then X3, X5, Z4 + 6 series etc were produced in between which i don't know their E no.s without researching, now we're up to E92 aren't we with the current 3 series, i may actually be talking balls though as i don't really have a proper explanation![]()
i'd guess this. Makes sense that whenever a new "design" is started it has a new E number for reference etc which is not anything to do with model classification or anything else. If the new design never makes it, then you will never see that E number on the road.

