Just to head off the comments early: as we get more data, we'll break out engine and body types so you can see all Jettas (including gas and diesel and sedan and wagon), then all Jetta diesels (sedan and wagons), then just Jetta diesel wagons.
hmm, yeah, maybe when showing a specific model year we could bold the EPA combined estimate on the graph or show it in a different color. Then you'd see in a glance if most people are getting above or below the estimated mileage.
The more I think about adding EPA estimates the more difficult it gets. There are different estimates for automatic vs. manual, diesel vs. gas, etc. just within models. So until we we're sorting at that level, I'm not sure how we'd show EPA numbers on this graph.