After Lowering my car with Eibach Pro-Kit springs(see review) I found it necessary to use spacers to remove the very apparent wheel inset. The Garageline spacers a priced very well and come in multiple sizes. I opted for a staggered set, running 15mm on the front and 20mm on the rear.
The design of the spacers, means you use the stock hub bolts and the supplied lug nuts to mount the spacers to the axle. You then mount your wheels to the spacers which have either own bolts, using your original lug nuts. This design makes for a simple bolt on upgrade.
Make sure your hub is clean, as any debris can cause the spacers not to sit flush, thus they’ll wobble. Also, make sure that you properly torque each bolt on the spacer; I’ve had mine come loose. This leads to my main complaint. The supplied lug nuts have a tapered top and the size of the recessed hole makes it very tight to fit your socket in there. These two things combined make it hard to properly torque the bolts as the socket tends to slip off.
Some people have suggested using blue lock-tite on them. I have not tried this, but if they come loose again I will.