I've had my Cube for 5 months. Three months into it I got a big crack across the bottom of the windshield on the driver's side due to a semi throwing a rock my way. Shortly after, it stretched about 18" across the windshield so I got it replaced. Exactly two weeks later with the new windshield I got a small "bulls eye" chip on the passenger side from a small rock thrown up by a car. Before that one had time to spread, I picked up a Permatex repair kit and filled the chip. So far, so good. It hasn't grown at all, even in all of this Florida summer heat.
It's not a defect of the glass but just the fact that the windshield of the Cube sits up so vertical that rocks want to go through it instead of deflecting off of it. Sucks really but waddiya gonna do?