i own a 1998 S90. have owned it for 14 months. I paid $6,000. in December 2007 for it in maryland a few things. I thought i read the following somewhere.

1. the 1995 and older had block issues with the inline 6 cyl. engine. B6304 engine. the block was porous causing coolant to seep thru the metal block casing. i think this was under the FAQ for 900 series vehicles

2. make sure that the maintenane on the timing belt it current. MORE IMPORTANTLY that he idler pully bearing, the tensionior pulley, water pump, dion't have more than 70,000. mile on them. i currently speak from experience, my idler pully failed cause big engine damage. i'm now pulling the head for a valve job. the timing belt only had 30,000. on it. it was fine. the other components where not changed out.

i love the car....