These caster/camber plates from Maximum were just what the doctor ordered. I lower my 2011 Mustang GT using Ford Racing M5300K springs, which caused my camber to go out of whack.
I bought these and had them installed at a local shop, and now have a lot more adjustability in the front suspension geometry than I had before.
Fairly affordable, easy installation, and the only thing other people see looking at the car are two small "Maximum Motorsports"-branded plates. 95% of this thing sits under the shock tower, keeping a clean look in your engine bay.