I think you better take a hard look at your suspension and Upper Camber Arms specifically. The stock ones do tend to wear out and then camber goes out because of it. Powertrix makes some good adjustable upper camber arms. Of course, these require the adjustable tension rods as well.
I think your issue could be due to worn out bits. The car is old. Try changing out steering rack bushings, along with other suspension bits. And while you are at it, why not upgrade?