I'm going to step out on a little bit of a limb here, because I know there is a lot of argument about this: I highly recommend that you do not, ever, jack up a Volvo by putting a jack under the middle of the front suspension crossmember. The Volvo is no lightweight, and though the crossmember is certainly a heavy duty fabrication, it is also the part to which the rack and pinion is bolted. I've heard people say that the cross member can be flexed enough to bend it, and I don't swear that this is so. However I would say it is better to avoid flexing anything that has something as flex-intolerant bolted to it as the steering rack. Tweak the steering rack and it may begin to bind. I always put the floor jack under the jacking points by the doors (where you put the car's tire-changing jack). I put a heavy rag on the saddle of the jack and make sure it seats solidly on the jacking bracket. The rag protects the undercoating. Once raised, I'll put the jack stands under the ends of the crossmember where the front a-arms attach or up front under the frame (second choice). If I need to get the car really far off the ground, I raise it in two stages. For the back I also put the floor jack under the differential (the big, round center of the rear axle, the "pumpkin"). Once up, the jack stands can be put under the axle itself of even under the big, rear, trailing arms. Once again, use something to protect your undercoating if possible.

Good luck, and happy new year,

Dave