what's that?

I've seen the pic of 95 PA - it has had plastic square (sensor ?) on the right side of the inside mirror (it's on windshield on the right side of the mirror) - could you tell me what it is?

It's a sensor to tell how hard it's raining so the computer can increase or decrease wiper speed.

In 95 model ????I've thought it was available only in newer model as 'moisture sensing wipers'

I shouldnt post on a friday night after having fun.,,,

I know the newer Buicks had the MS wipers, that box might be your compass.

Could it be the light sensor for the auto night mode mirror?

The light sensor for the twilight sentinel is on the dash in the black piece that goes the whole way across. It's the little black ball in the vents on the black piece.

I'm almost 100% sure its for the compass.