I don't know if anyone has mentioned this before, I'm sure I can't be the first to notice it. But...
In the third trailer at 00:24 we see the underside of the Kelvins main hull. The center where the sensor dome would be is very flat, no real dome.
Now at the end of the trailer at 1:59 it appears different. It looks as though another section of hull has dropped down from inside the saucer, it has windows on the front and what looks like a phaser emitter hanging from the bottom.
Also the image appears to be reversed as the lettering is right side up but backwards. Maybe that so you can read it in your rear view scanner.
Also at 1:48 the underside of the Enterprise secondary hull has large recessed area with lights, not sure what that is about?
In the third trailer at 00:24 we see the underside of the Kelvins main hull. The center where the sensor dome would be is very flat, no real dome.
Now at the end of the trailer at 1:59 it appears different. It looks as though another section of hull has dropped down from inside the saucer, it has windows on the front and what looks like a phaser emitter hanging from the bottom.
Also the image appears to be reversed as the lettering is right side up but backwards. Maybe that so you can read it in your rear view scanner.

Also at 1:48 the underside of the Enterprise secondary hull has large recessed area with lights, not sure what that is about?