Has anyone installed springs from The Progress Group? Howd they run and was the spring rate effective? Those mushy eibach sport-pro-somethings just arnt gonna cut it. I was gonna go with the ground control set-up and get the benefit of the Eibach ERS springs but the cost is getting to me and the need to adjust my ride height without the use of sophisticated techno backing seems hazerdous to handling. The progress springs are supposed to be designed for autocross and roadrace....so anyone?