The rear wheel adjustments include camber and toe-in. A weakened or broken rear spring might cause the rear suspension trim height to be out of specification, but I don't think it would cause either camber or toe-in to be out of range for adjustment. For one thing the rear shock, which is separate from the spring is self-leveling. Additionally, people install lowering springs on Vs all the time without running out of adjustment on camber/toe-in. Has this car been in a collision?