While working with my '89 GL Coupe, I have often noticed when the hatch is
up, the lift struts have wiring running along them. Huh? Why is there
wiring on the struts?

Then I looked again. The body of the strut has like a cup with metal
surrounding the inside of it, and the other end has what looks like grease
fittings. Hmmm...

Then, I looked AGAIN. When the hatch is closed, the knob-thingys fit into
the open end of the strut, where the metal cup is. Hmmm...

OK...when the hatch is closed, the knob/contacts make contact. When the
hatch is open, the contact is broken, and the REAR WINDOW DEFROSTER can't
turn on!

Pretty neat. I'll have to take another, closer look to see if the strut is
something that has to be bought from Subaru...