Suddenly neither rear side window will go down using either the driver's control button or the passenger's. Any suggestions ?

Its possible the window switches are bad. This is a common occurance with that car (i had the same problem) You can try cleaning the switch contacts or replacing the switches. Otherwise I would suggest checking the wiring to the window motors to make sure those arent loose.

Is is likely that all 4 switches would go bad at once ? I was thinking more of a broken wire leading to the first switches in the circuit.

Any suggestions as to how to gain access to the switches to see if they are getting power?

Thanks in advance.

Henry

It is unlikely but it is possible. I had three of four go at once about a year ago. As for accessing the switches. You can try prying them up from above with a screwdriver but that is likely to damage the switch and/or the door panel. The best way to do it is remove the door panel and push the switch up from below. To do this remove the small plastic cover in the grab handle (looks like a round corner square, pry it off with smal screwdriver or fingernail) Remove the torx screw you just uncovered. Move along the bottom edge of the door and pull towards you. It helps to have a trim panel remover but a screwdriver works here to. Just be careful with a screwdriver not to damage the panel. Work slow and you shouldn't have to worry about breaking any clips. If you do break some they are cheap and available at dealers and most parts stores. Roll down the window and push the panel up out of the channel it sits in at the bottom of the window opening. Thats it. The door is out.