[Kev0607]

Rear shocks are a doddle to replace. At 133k, its likely they'll be worn anyway. Being honest, the same applies to the front. If you've got no record of them ever being replaced, its likely they could be original too.

If going aftermarket, go with Bilstein, Sachs or KYB. Use good quality mounts too.

Parts for Volvo is a good place to use. Just put your model/model year in, go to suspension and view what they have to offer. Last time I checked, they did a kit (front and rear shocks) for £221 (Bilstein B4's). Whether they still do it, I'm not sure. You have to buy the rear mounts separate, as well as the top mounts for the front (if you do them). The kit doesn't include those, nor does it include the springs.

Its up to you if you replace the springs though. If they aren't cracked, they can be reused.