When I bought the GX, a previous owner, converted the rear door locking mech to a gas piston. It was snappy, if you open the door and let go, it would flick open pretty hard. So I was just in the habit of slowly assisting the door open.
Took the GX thru a simple carwash a couple weeks ago. They probably just let the door fly open and it busted an end of the gas piston. I was more annoyed no one there said anything to me about it, since I had to find out on my own when I got home.
After searching here and the FB group, the kit used by most has shot way up in price, especially for what it is. So I found a comparable rated piston and bought a 2 pack off amazon:
They arrived and I went to install them, only to find out that the ball stud also got bent. So I ordered some new ones:
new vs bent
Installed the new stud and put the new piston on, and the setup did not clear the underside of the door when closing... Not idea what the real difference was, it looks like the new stud was a tiny bit taller above the nut vs the old one. So I removed the plate that the stud screws into, took a cutoff wheel, and trimmed it down a bit.
Shot it with a quick coat of paint on the raw metal
Brought it back to the car, bolted it back in, installed the stud, the piston, and everything worked fine.