Those springs should have a higher load rating than the stocks to prevent exactly all the things you are noticing... I'm wondering if you don't have a bad set? Those are terrible odds that all four would be defective, though... Do you have a local performance shop you can call and get the spring rates checked? Or send Eibach an email and ask them if there may have been an issue with an affected lot of springs... maybe they know about it but it was only 10 sets worldwide so they are not going to hunt you down to let you know.