I'm noticing a creaking noise from somewhere in the rear of the car, perhaps the parcel shelf or rear seat, whenever I go over some bumps, or every time I back out of my driveway onto the road (when the car flexes, presumably). Any ideas? It's not terrible, but if it is an easy fix, I'm all for it.

Also have a rattle/tapping noise from the base of the windshield (about middle of car) when it is cold. Based on searches, seems this is common...

 

The only way I could fix my creaking was a combination of the GT Spec bracing...and WD40.

I had/have exactly the same as you.

-s-