well you never know because one day my car started to pulsate really bad while braking and when i pulled out the bushing it could be separated by hand meaning broken! what the dealer does is probably puts it on the lift and gets a pry bar to try and lift the rear hub to see if there is play and if there is more than what the manual specifies then they tell you it needs to be changed. if your in doubt of the dealer ask them to show you the old bushing after they change it if its not worn you can do what ever you can to not pay. and if you dont change it because you dont think anything is wrong then this could lead to more severe problems, un even and accelerated tire wear pulling to one side...etc..