I think my shocks and struts are messed up, cause i hear a sound on the passenger side rear everytime it hits a bump. Anyway, i was wondering, there are 4 shocks and 2 struts....on the rear? of my mustang....or how is it arranged. What needs to be replaced? Is it ok to replace just the shocks? Or just the struts? whichevers making the noise? thanks for your help