With how much vehicle performance has been tweaked, I haven't really got the slightest idea what anything is doing anymore, because every part ends up being a tiny variable in a presumably complex hashed outcome and they often have little or no documentation except the object name and price to glean information from.
Some kind of diagnostic tool to get basic information about vehicle performance would really go a long way to making it something more than a mystery box. Potential things like mass, handling, velocity, an odometer, a digital fuel gauge, hardpoint information.
Characters can see how equipment effects their @stats, and modern vehicles usually can display a fair amount of information, so I think there's some logical precedent for a certain amount of data to be visible.