That sounds like a pretty amazing trip to me, there is just something about driving out in the desert, during a warm summer night, while blasting some 70's rock, that's paradise right there for me.
The Grand Canyon...the pictures & movies do not do it justice.
Have you thought about going to Monument Valley, on the Arizona-Utah border.
How about making a stop at all the famous places movies have been made on your trip?
That would be so much!
If you make it down to TX, I would recommend NOT crossing the border at El Paso to go into Juarez...not a nice place to cross.
“Love me or hate me, both are in my favor...If you love me, I'll always be in your heart...If you hate me, I'll always be in your mind.”
-William Shakespeare