Hello Chris,
What you describe about the control arms is right. That's how it's done on the 02s and 03s. You can ALSO use the TOP bolt of the late suspension to get more camber. This is done on the Golf, 924/944/968 who essentially share the same suspension setup.
And YET another way is to install camber plates and they allow the shock/damper piston to be held in a particular setting you like, and since the piston and strut lies in the same axis, hence you get more camber adjustment. Of coz some plates allow caster adjustment too.
Sprint.