dont use that seat. that is for the 06-07 spring. use the seat that comes with your car which looks like this.
and end up like the one on the right. the one on the left is the one with the 06-07 spring with the top hat in the pic you posted
if you think about it, if you buy 08-11 springs, it should be a direct replacement for your stock springs. everything made for a specific year should be a direct replacement. idk where you got those seats from but send them back. you're good