This is a fantastic topic. I'd prefer to redesign the entire interface. Flatten the hierarchy, because it's too distracting to have to navigate up, down, left, and right within a menu tree while trying to drive.
Create the following display choices. Use the up/down arrows to cycle through them:
1. Trip meter #1. Display mileage, time, and mpg. Double right-click to reset all three in one go.
2. Speedometer. Show current speed, distance to empty, mpg since startup.
3. Trip meter #2. Display mileage, time, mpg. Double right-click to reset.
4. Traction control. Press OK to toggle between "Disable Traction Control" and "Enable Traction Control".
All displays can include the outside temp and compass direction at the bottom.
I include the traction control toggle for quick access. The times I need that feature are almost always when I'm stuck at a stop sign and unable to move, and cars are piling up, and I need to disable the feature quickly.
I put the Speedometer display in between the trip meters on purpose. That way I can make the speed display my default, and I can get to either trip meter with one click.
No need for a hold-down delay on resetting, nor for any sub menus. Just let me right-click twice quickly to reset the trip meter, so that I can get my attention back on the road. Reset all all three data elements in one go.
One click on the OK button from Display #4 toggles traction control. That's fast and easy, just what you need when under pressure to get moving in a snow-covered intersection.
No need for any submenus at all. They are just a distraction and a danger. Eliminate them. Simplify. Reduce cognitive load from having to drive the interface. Make the goal always to return attention to driving as fast as possible.