Probably something to do with gravity working the wrong way round down there
Seriously: that sounds like grounds for a new matched pair of rear springs under warranty to me. It can't be regarded as a satisfactory remedy to remove one lowering block! That effectively gives you two different spring rates - which can't be right.
As to the fronts: I'd want to see careful measurements made of the ground clearance either side at the front after the rear springs had been replaced. Then a decision could be made on whether fronts need replacing too. Guess it's not beyond the wit of man to measure the free length of each front spring - unloaded - if they differ, they're obviously not right and
must be changed.
As to the cause - who knows? Wonder if the car was wrongly strapped down during shipping?
Those are my thoughts at any rate. Hope it helps!
