I installed a pair of aftermarket (Ebay) $37.99 rear lift-gate hatch supports
. Significantly less expensive than the OEM part. What I discovered was, if I replaced both, the hatch came-up VERY enthusiastically and I had to invite Arnold Schwarzenegger over to close the hatch; previously, with the tired-out OEM originals, I had to have Arnold open the hatch. I then removed one of the new supports and re-installed ONE of the original supports...perfect, hatch comes-up smoothly on its own and is easy for my wife to close the hatch. Plus, I have a spare! No need for Arnold any more.