Best option for springs is COBB. 215's are .31" taller than the 205/40's. Doing the math, the ST is dropped .8" from the factory, + 8" COBB spring drop, + .31" (IIRC)tire height = ~ 2" total drop. This is going to be very close. Springs will either drop too much, or not enough. The COBB springs are more friendly with this set up, but a 2" drop is right at that margin. Coilovers, like those from ST, are very friendly starting out at a .2" initial drop up front for a 1.31" starting drop w/215/40's.