My 06 did the same. I was told the glass was not cut right so the bead didn't seal. After the dealer replaced the glass there was still a leak....from a body seam around the window. It was a huge problem but now it's nice and dry. I am sweating this summer and mildew from any extra water that might have traveled forward in the cab. Take yours back and have them fix it.

 

I agree with FFmedic, that's a new damn truck and shouldn't happen. Make em fix it!