Personally i don't have a 2012 but if you can do it, put the crossover inside of the car not the door. The constant banging of the door opening and closing can do a lot of harm on a crossover. I had a crossover in my door and it constantly kept dismounting itself (my poor mounting but you get the point). so if you can hide them in the rear quarter panels somewhere and run wires into the door i would say that would be best. again i don't have a 2012, if there are separate tweeter and mid-bass wires running out of the door splice there so you don't have to run into the doors.
Mounting in the kick panels would certainly be beneficial, as was said, but a hell of a lot of work running wires through the door boot/molex. Just make sure the crossover is secured inside the door very well and not in an area it may get wet. Some people even stick them inside rubber gloves for added moisture protection (heat is never really an issue with crossovers). Should have years of service-free performance.
Careful of those foam inserts my 2002 has the same thing and I cut them out to fit the crossover in it and I had attempted screws, double side tape, Velcro, and duct tape nothing really works haha make sure they are very stable before you finish