How to Put in Neutral With a Dead 12V Battery?

You can't open the hood because the cable is broken. You don't want to open the trunk because it's a PITA.
That leaves your options pretty limited since taking it out of park is performed by an electric motor.

What type of terrain are you trying to move the car across? Maybe some of those roller devices that you can put under the front tires? The rears should just roll if the brakes are released.

 

Getting into the hatch area may be a PITA, but probably less of a PITA than getting under the hood with a broken release cable, so I think the hatch would be my choice, and connect a jump pack, and turn the car simply ON (two button pushes, no brake), and shift to N, and you're done. (Powering off will shift back to P, so save that for when you've pushed the car where you want it.)

 

There is. It just requires popping off a small plastic cover (and a flashlight if you're not familiar with it). Definitely not as easy as some, or as obvious. Could probably rig something up using one of those pull handles and cords from another car and attach it to that lever. Woohoo..another project for a day when I'm playing around.

 

Of course the way the universe works if you go to all that time and effort to add a rear hatch release cable for emergencies I bet years would go by without a chance to use it.

 

i've crawled in the back once in 18 years. it really wasn't that bad, read the o/m, flashlight and screwdriver, voila! two minutes