When driving the Javelin on DC the speed limitation indicator is in imperial units whilst my settings are in metric. Also the loop for the engine sound needs to be tuned. The loop start is not correct so you hear it's a loop instead of an engine.
When you switch to dc, the javelin will always use Imperial units to match the signage on the UK domestic network. It uses metric for the hs1.
But it should stay metric in the HUD (Upper right corner). It should always stay metric in the HUD as is indicated in the settings.