+1, I was really surprised to find that this is not already part of Carwings.
Something that runs on your phone is great for locating your phone, but that does not work to find your car because your phone is not usually in the car. In fact, you are using that phone to look for your car, aren't you?
I am seriously considering adding a phone that always lives in my Leaf just so I can run the "Where is my Leaf" app. This would be a wasteful duplication because the car already has a GPS and AT&T wireless service and could theoretically do more things with them.
The other related application I have in mind is keeping track of how much time and power each segment of road actually takes. This would allow making an "efficiency map" that could help plan routes and compare how well you are doing vs. your or others' history for this route. Distance per kWh is nice, but how well am I doing going up this hill today vs. my average or best?