Alright here are your measurements as close as I could get them. Pretend your looking at a right triangle.
The Alero is 6.5"H, 6.75"W & 10.5" on the angle section.
The Intrigue is 7"H, 6.25"W & 10.25" on the angle section. The Intrigue has a wider gasket around the window, the Alero does not.
With that gasket on the Alero it looks like it is gonna be close, very close.
plastic can always be modified or manipulated if you have to.
The Intrigue mirrors also are breakaway type meaning the fold in if you hit something.
I would go to a Pontiac dealer if possible and talk to their parts guy and see if he has more info. They would be more familiar with the Alero than a Caddy dealer.
GOOD LUCK
