Join Date: Nov 2001
Location: state of confusion
Hitting a bad bump in the middle of a hard corner might still manage to shake things loose. I had the same concern with the revised camber settings I used on a Mazda 626.
I used four washers close-fitted to the strut bolts with little tabs welded to one face at the ID. One washer per side goes between the bolt head and one strut 'ear', another between the other strut 'ear' and the nut. The function of the tabs is to fill up the spaces in the oversize strut ear holes on the +camber side and prevent any simple sliding. Since I no longer own that car, I'm guessing I used fender washers with the holes redrilled to suit the bolt diameter with as little clearance as possible.
It's much harder for vibrations to get both washers on each of your adjustable bolts to rotate in sync even in round holes, which is what a camber slippage would require. But grinding a flat on each washer or coming up with some other method to visually verify that slippage has not occurred might still be worth considering even for slotted holes.
Mine: '08 GT, 5MT, black/light graphite, un-Fstock (DD, occasional track day)
Wife's: '10 Legacy 2.5GT (DD, six-speed manual)
Spare:'01 20AE Maxima, 5MT (also my bad weather alternate)
Various Loose Parts: '79 Malibu