having troubles with camber adjustment

[MikeySand]

ok so after putting a poly bushing kit. coilovers and all the suspension arms in the rear i sent my car to get aligned after setting the ride height i wanted. the car came back with positive camber in the front to the tune of 0.8 on both sides. now the rear is perfectly okrunning about 2 degrees negative. i popped the hood to check the camber plates and they are set to negative. mind you all the installation was done by my father who is a certified bmw mechanic. now what he says is that ive set the car so low that due to geometry of the suspension it started to push the wheels positive instead of negative, now i dont know if this is correct. his solution is to buy front control arms so that i can adjust my camber further. is this the only solution i have? what could this problem be due to? thank you for your time and input

car info:1996 240sx SEwheels are work emotion xd 9 18x9 +20 fronts 18x10 +17 backsrolled fenders