a 325 uses 51mm diameter shocks. a 320 uses 45mm shocks. i dont know about the ix specific differences.unless its a touring like my sig then they all use 51mm struts. the springs will be the same on a 320 and 325 as theyre both 6 pots. touring spprings are stiffer than saloon springs so wont give the same ride height if interchanged..