Although it's mechanically the same car as the previous FWD 850s, the '98 X70s were the first year of that body and interior change and like most other "new model year cars", it was the most problematic year of all X70s and most were just minor electrical problems, nothing major.
The good news is that by now, most '98 X70s have probably been fixed under warranty so odd are good that if you bought one, you'ld be spared of all the minor inconviences.