A repair shop has recommended we replace all four struts because one in the back is leaking. Also the rear tire is wearing badly on one side so it needs to be aligned after struts are replaced. I'm limited on funds and do not want to do the front if I do not need to. Apparently I need to have all four aligned because it is all wheel drive. I look at the front struts and see they are much larger than the back and think, "Why should I replace these? They will prob last a LOT longer. Can I just replace the back struts? The car has about 50,000 miles on it.