Driver profiles so you can see all drives by driver instead of just by vehicle. That way when two different people drive the same vehicles, you can see separate driver profiles. Also, a per drive score would be nice to see.
Good news, the way you described the per driver interaction is exactly how it works right now. In your app timeline, you only see drives where your phone connected (and presumably you were driving).
Per drive score is something we've thought a lot about and will likely reveal in the future. No date set yet, but shouldn't be too long. Meanwhile if you are a developer, you'll be able to access per-drive scores through the API very soon. :)