---SNIP--- You can get them at bus depot but boy oh boy are
they strong.  It takes some muscle to really close the hatch now.  I
think
it was advised to replace both at once but not really sure why now.
---SNIP---

Yeah, I think that they are ridiculously  strong , I can barely close the
hatch with two hands!  Try it with one and you'll pull  a groin muscle.
To put numbers to it, it take 23 Lbs of force to start the hatch back
moving with the force increasing to an even 50 pounds on this hot day!

To be fair, I complained to Ron, and he offered to take them back.  He
stated that I was only the second person to complain - so all you westy
owners must be a lot stronger than me!  I did not take him up on the
offer since I thought they would "loosen up" - they did not.  My wife
could never close this hatch back though.