Not so much bug as a feature request.

To reproduce: "vehicle driving assistance": none, and "manual clutch": yes and while using non-automatic car.
From driving in first gear by the use of the accelerator, let go of the accelerator and observe the engine stall and stop on level road. Even a tractor will do that same and not make it further than if it was in neutral.

This level of detail is now present in the ability to engine brake downhill in different gears, even with an empty vehicle and even with the engine off. I wish to see idle to be brought to the same level of detail.

Suggestion: Add a constant low input of the accelerator (idle) whether or not a player is inside, allowing the player to roll while looking at map/talking with pedestrians etc. without messing with the clutch (it has a good feel). It also allows for a self driving car, which can have funny applications.