The rubber strut dust boots on my 13 year old 2012 Prius v deteriorated into shreds when they were inspected during last month's annuat tire rotation. While nice to have to extend the life of the struts, they are not absolutely necessary, since the struts are not leaking as the car's mileage just turned 34k miles. It is important, however, that the often called "spaghetti" debris be removed, which I did. Some three minutes into this video about replacing a failed Highlander strut revealed how a piece of the rubber debris might have contributed to the failure of the strut's seal as a piece was wedged into the gap between the shaft and the seal.