Update -- both front ones must be blown. In just a few days of driving it I've experienced all the telltale problems: loose cornering, serious wheel hop while accelerating, and yesterday while leaving the light the wheels were so busy going up and down they were barely going forward.

Here's my next question -- if the price difference between stock and perfomance is so little that it'd be dumb not to, I suppose I absolutely have to replace all four with aftermarket, right? And if that's the case, would it be completely retarded to stick with stock springs? Money is the issue here. What do you think?