Why does my mazda 3 S Touring have a windshield rain sensor, but no option to use it?

The Grand Touring is the only vehicle set up to use the rain sensor.

Does anyone else have a 2009 Mazda 3s Touring HB that has the sensor on the windshield?

Can anyone enlighten me?

 

I think I may have replied to you over on M3F, but... whatever. Anyway the rain sensor is built into the mount for the rearview mirror. If you're talking about the black "dot matrix" dots above the mirror those are just black silk-screening on the windshield to help reduce glare.