windshield wiper wipers

This is getting frustrating. The first year the automatic wipers seem to work correctly and I would normally leave them on all time without fail. But last several months, they have become erratic. Light rain, they work correctly and then just start going faster and faster to the point I have...

I'm wondering if anybody else has noticed the REAR SMART WIPER ??? Although the rear wiper CAN be trigger from the column, but if its SWITCHED OFF, and the Front Wiper is ON (any mode) and you shift into REVERSE, the REAR WIPER goes into DELAYED WIPE mode. Quite Smart for a SMART!! :rolleyes...