Worth the extra premium, weight and less mpg over a 2wd ? Expensive for a small car, BMW E39 530d and E46 330d territory. Advice, and must do mods. Has it a dual mass flywheel and is it best to convert to single mass ? Will a Stage 1 + 50bhp & 50ft lb remap kill the clutch. And what conversion and or clutch for Stage 1 for a near stock feel ? Many thanks.