[throwaway19972]

> I would want to do it with my phone because then I only have to have one thing to carry around with me.

I would prefer this to be a keyring over a phone for aforementioned reasons. Secondly, the app is buggy and often just fails to work. Third, it takes a good deal of time to take out the phone and fumble around with the software.

All in all, it's a pretty miserable experience.

[allannienhuis]

I rarely need to open the software to make my car open the door automatically. Once in a blue moon I need to actually open the app to force it to connect. I actually can't remember the last time I needed to do that. It's normally completely seamless. The phone stays in my pocket - the doors unlock when I'm nearby, and lock when I leave.

That's my experience of course, other car apps might be much different. But that's an issue with the implementation, not the concept.