Rearview mirror auto dimming- how turn off?

[billme247]

Does anyone know if there is a way to permanently turn off the auto dimming feature on the rearview mirror. I think my tinted windows in the rear are sufficient, so I hold the first button switch down for 3 seconds and the dimming feature shuts off, but the next time I start the car it defaults back to "dimming feature ON." Any suggestions? Thanks!