i have a 94 with the same problem. have you had the heater core replaced? Mine had been replaced and the shop my ex girlfriend took it to busted the cover for it which also directs the condensation from the a/c to the out side. so I sealed the all up but im still having leaking issues. check around the heatercore cover after you have drivin the car with the a/c on. Let me know f you find anything new as i have the same nagging problem...