I have a 97" Pontiac Grand Prix and I am trying to find out whether or not if I need strut mounts or struts. 1st how can you tell if the mounts are gone bad? 2nd how can you tell if the struts are gone bad? On the otherhand, which one only last for about 30,000 miles then wear out? Is it the strut, if so how long do the mount last.