You can purge it anywhere, depending on if you want people to see it or not. Under the hood is fine if you want it hidden, it's not flammable or anything. I've done it out the center of a cowl induction hood, making sure it wouldn't hit the windshield on a hot day.
I purged up through the windshield wiper panel, in the center but following the edge toward the passenger side of the windshield. That way it doesn't fog up my view, it is still discreet when I need it to be and gets it out of the engine bay.
If I'm in a grudge match I'll either "purge" it into the intake by sitting in neutral and hitting the launch button simultaneously with wot...or I bump the button a couple times while in the burnout box. Both are stealthy enough lol
Cant think of any cool places to purge from on the 13/14 aside from the hood vent. I always liked how the terminator/gt500 guys would have it from the snake
A lot of it depends on where you mount the solenoids too. I think the hood vent is a very good idea. Only problem I foresee with that location is, it may require the use of nylon lines which would be more flexible to make opening/closing the hood a non issue. I tried using the aluminum purge line that came with my purge kit and it was a PITA to conform to the route I needed to take. I ended up having to order a custom length line with b-nuts already installed on both ends for my purge and it worked much better.