Time to do a tune-up on the old Volvo. It’s a ’95 940 non-turbo 2.3L US model. The distributor cap is mounted behind the motor, not next to it. Apparently to buy the correct distributor cap and rotor button I need to know if the car has a Rex or Regina system. I have no clue and don’t know how to tell. So can someone clarify for me the difference between Rex and Regina? I’ve made 3 trips to Advance Auto Parts and Autozone and they haven’t been any help in clarifying this for me. They have all said they don’t have the caps and rotors in stock, so I’d have to order them. I don’t want to waste time and money ordering the wrong parts. They are expensive!