had mine replaced a couple months ago and I just got a new crack all the way along the bottom of it. Crazy.

 

jjones, take the windshield back to the place you had install the windshield. It is possible that if they didn't seat the window correctly, they overly stressed the window and something as simple as turning on the defrosters can add a little bit more stress and cause the window to crack for no apparent reason. You can prove it is a stress failure because along the whole crack, there won't be a chip of any kind. I had this happen on my T-bird and the shop replaced the windshield for free.

 

this is exactly what happened to me. I will try to get them to replace it for free.

 

I've had mine replaced 3 times (total of 4). They seem to be prone to cracking in my experience.