Some people will say you'll need them and if you don't you're going to have uneven and severe wear on your tires. They're not expensive so if you wanna be safe go for it but I've gone a year with the Eibach springs on without the camber bolts and my tires have been wearing evenly.
Say what? Last I heard, you only need them for the front.
As for the original poster's question, you may or may not need them. The Eibach springs only lower the car 1" to 1.2" which is not enough to cause a major change in the geometry. What will change significantly is the toe-in, so you must get an alignment done. If the shop doing the alignment cannot get the camber into spec that's when you need the camber bolts - one for each side at the front of the car.
I lucked out on mine and the shop was able to get the alignment without them. He did use a spreader tool to force all the slack in the mounting bolts in the direction necessary to get the right camber.
Adding-on what lleader said, yes they're only for the front. The back suspension don't use a spindle, so the bolts would be useless. To do the backs, your going to need a camber plate, and I don't know where you can get one for these cars.
To install them, you replace one of the two (I always pick the bottom bolt, but the instructions say the top one) bolts and replace it with the camber bolt.
The "handle" faces towards you while the "tab" faces towards the car. Before tightening the bolt in place, rotate it to the desired degree...then tighten down.
The diagram below is a TOP view of your suspension.
Though they will begin to "roll" and you'll be at 2* of camber within a month...no big deal.