I'm going to try letting everyone know about this one more time, and if no one's interested I'll let it die. I've got my Volt stats website up and running here:
I haven't had as much time lately to work on it as I'd like, but it's functional and I've been tracking my Volt's stats for a couple weeks now. I'm interfacing with the webservice that the mobile apps use, but I'm really curious to see what the enhancements are to myvolt.com that are "coming soon", and hopefully I can interface there if the data's a lot better.
Anyway, my goal is to get a leaderboard together where we can compare everyone's stats. Yes, this means you have to register your Onstar login/password with the site, but without your Onstar PIN I don't think there's any way I could send any commands to the car. I've also published the source code to github in case it'll make anyone feel any better about registering their car on the site:
It's an ASP.NET MVC 2/MonoBuilder project, although it could easily be converted to VS 2010 format. If anyone would like to contribute, or even rip it off, feel free.