Insted of wrapping the 'u' shaped striker on the window with tape and having it get all sticky and nasty looking, I went to a NAPA store and got a can of a product called Plasti-dip. It`s that stuff you use to dip tool handles in to rubber coat them. It comes in a bunch of colors, I got black. Just follow the directions on the can and it works great! You don`t have to take anything off and it looks like a factory install! It`s not cheap, about $13 a can, but if you find another owner you can split the cost and dip your plier handles! I gave mine 3 coats to start with, and you can always recoat as needed. The part # is 765-2502.

 

I'd pay close attention to the hinge bolts before writing this off as a hassle-free fix. Overtime the bolts that secure the rear glass to the two hinges will work themselves loose. The crappy hinges will eventually strip out from having to re-tighten so I suggest drilling the existing holes all the way through and securing everything with a nut/bolt/washer arrangement of some sort.
I'll have to maybe try the plastic dip if I ever find some available in cheap supply, until then I'll just keep dabbing a bit of grease on the latch and keep everything adjusted accordingly.
Damn blazers...

 

I just replaced my driver side hinge yesterday, due to the glass bolt being stripped out and constantly falling into the back trunk area. But Ialso have some tape wrapped around my U thingy anyways. I didnt do it, previous owner must have, it does look nasty and worn out.

 

Another idea to fix squeak
There is the "U" shaped latch on the glass and also the pin typ peice
If you look where the pin pice goes next to the peice that actually latches onto the U youl notice theres a bracket
There is suposed to be a peice of plastic that goes in and that keeps the window from rattling/squeaking
If you put a rubber wire grommet in it will also fix your problem

p.s. Sorry about my spelling just got off of work
p.p.s. Ill try and post a picture of what im talking asbout

 

my rear window rattles too lol what is the u shape u guys talking about? i am hard to find it

 

What I've always done is adjust the bracket inside the tailgate that the rear glass hooks into. By changing the position ever so slightly, you can get the glass to close tightly onto the tailgate and VIOLA! No more squeaky rattle! (Just be sure not to make the fit TOO tight, otherwise the rear window release button may not open the hatch! I learned that by trial and error...LOL)

 

Manny - The U-shape bracket is on your back window. Open your window and where it latches into the tailgate, its a metal bracket in the shape of a U, and right next to it is a solid straight pin. The bracket and the latch in the tailgate rub together during driving and cause the squeky noise. Some people put tape or a small piece of cloth/rag around the bracket to stop the metal on metal rubbing.

 

Ya, Redeye, I adjusted my latch too, and you are correct, there is a fine line between not rattling, and the release button not working! However, even after adjusting, I still had a small rattle. That is where the Plastic-dip comes in handy. Some guys don`t care about the buttons, and just adjust it very tight, then just use the key to open the window. I can`t do that, my wife won`t let me! Besides, I think that would cause accelerated wear on the striker.

 

And I can't use my key in the hatch either because I loaned the blazer out to someone who couldn't figure out how to open the rear....and broke the latch! (Yes, they did not see the "Rear Window" button on the dash!) So I replaced it with with a wreck and I HAVE to use the button because I couldn't get a key for it. And I do still have a "slight" squeak over rough roads, so I think I will try out the plastic in the near future. Thanks for the tip!

 

Redeye, that is why I don`t let anybody drive my vehicles, especially my inlaws!
I bet a locksmith could reset that lock cylinder, { for a price }, so you could use your key again.