Negative rear camber

[uncle]

My E36 with factory sport suspension, OE Boge shocks, stock wheels, correct size tires, good supsension components (RTABs, etc.) Has negative camber even after a recent alignment. Using the lower adjusters, there is no more that can be taken out.
Why is this the case on these cars? I know the lower struts are the same part number for standard as well as sport suspension, and if this lowered the car (from stock) could cause some of the camber.
But, it seems to me that this should have been a consideration when egineered and manufactured.
I am curious if anyone has an understanding of this, and a solution other than adjustable lower arms?

[Pierre3400]

Are most of the bimmers not born with a slight negativ camber on the rear?

[monko141]

Stock Is's are suppose to have -1 degree and m3's are suppose to have -2 degrees negative camber in the rear. Bimmerworld has the cheapest adjustable rear trailing arms that I have found.