Caster on the E9x and E8x chassis is VARIABLE during the turn, unlike most strut suspended cars. For most cars we ship Vorshlag camber plates in the full-additional-caster position because most chassis need more caster and the only way to get it is to change the static caster. But the E90/E80 have dynamic caster provided by the multi link lower arm. We ship camber plates for those chassis in the no-additional-caster position as we feel they already have enough due to the unique suspension.
Jason McDaniel at Vorshlag