So, I've got the same issue in three of our family's Subies, all wagons. At the rear wheel well, reach up under the fender and into the strut tower on the outside of the coil, under the window and you can stick your fingers thru a nice, long rust hole... guessing along a seam in the metal from the way it feels. You can push and feel weakness in the metal around the hole. Reaching around to the areas in front, behind and to the inside of the strut / coil feels solid.
A mechanic has said maybe he could get us a year on the worst one, a 97 Wagon GT. Others speak similar doom and gloom. But then I discovered the same issue on our 1995 L Wagon, which is in excellent condition otherwise. Our 1999 L Ann. Edition is a rust bucket anyway, and it's similar in the towers. Both the 99 and 95 have been good, regular daily drivers, and the 95 in particular should have a lot of life left in it otherwise.
So.... from the experts here, I seek prognosis..... Doctors? Tell it to me straight.....
1) How long have we got? 1 year, 3 years?
2) How can we tell how bad it actually is? Is the fact that it seems only outboard and not all the way around the tower a good sign?
3) Is this something that can be fixed, or is it normally too expensive to be worth while
Thanks for your input.... as always!
Mike