Has anyone had windshield wiper linkage problems how did you fix ?
Also both rear door latches have failed (door won't shut) dealer wants $500.00+ to replace any ideas ?

 

The answer to your first question is yes, some folks have had wiper linkage failures. Give this thread a read, just click the link below...

https://www.chevyhhr.net/forums/how-tutorial-library-21/how-fix-wiper-transmission-32975/

For the second part of your question, I'll ask the obvious thing first, have you tried lubricating the latch mechanisms?

The GM part number for the left side rear door latch is 25811543, the part number for the right rear latch is 25811544. They list for $131.67 each, but you can find them cheaper with a quick Google search.

If you're mechanically inclined, you can replace the latch assemblies yourself, here's a nice "How To" video on removing the rear inner door panels.(Thanks to the folks at 1AAauto)

 

Or try the fix somebody suggested last week to a similar problem.

Use a screwdriver to flip the mechanism back to the "open" position, then lubricate.