The rear shock and rear trailing arm?
I know the front wishbone needs to be done with the weight on the wheels and I believe the torque is 90NM + 90degrees which equates to FT using an 18inch breaker bar (a crappy one anyway). If you are fan of weight lifting then maybe just go with quite tight.
As for the rear shock, I wouldn't go over board. It's probably a lock nut and nice and tight will probably do. 90NM is probably okay, its not that tight after all. Your real guide is the size of the nut and bolt and the fineness of the thread.
I found some torque specs but don't think it covers any of what you are doing.
http://www.volvohowto.com/volvo-s40-...-1995-to-2004/