My '97 wagon with 3rd seats, just alot of minor problems.
There's been discussion about the safety of the rear facing 3rd seat, you can find an offical letter from Volvo to answer the safety of the 3rd seats. I think it is in one of those sites that talk about Volvo accidents.
I'm still not 100% convince that it is safe fro my kids, but just to have very occasional use and short trip is fine. My elder kid cannot use the 3rd seat, as we found out that she has rear facing car sick, we had to clean up at least 3 times, and that is fro her. My '97 also come with 2nd row built in booster in the arm rest fro wagon.
I do not feel safe with the open cargo area, as if items will fly to the front (not happen). I do not have the steel cage between the trunk and 2nd row, as kids seat there may need assistance. I do not have the wire mesh that pull out from the back of 2nd seat, as the child seat enchor belt block the way, I know it can be 40/60, but still cannot protect the child and driver. I just put on the cargo cover.
It is very hard to put two wide base full size child seats side by side, it is hard to latch with the shoulder belts if side by side.
If you want side seat-bags, you need to go fro at least late '95 or early '96 model, you can see the SIP words on the bottom of B-pillar between doors.