[MetroMPG]

Most modern cars have aero-unfriendly "A pillar channels" that direct water from the edges of the windshield up to the corners of the roof before releasing it. They likely contribute to the typical A-pillar vortex formation.

The 1995+ Metro does NOT have A pillar channels - instead there's a continuous transition from front glass to A pillar to side glass. Maybe better for aero, but water will stream freely into the car if the side window is cracked open even the slightest amount when it's raining.

Hard to say whether they did this for aero or cost cutting, but I'd bet on "B".