I've got a week old V40 CC with manual gearbox and D4 engine with less than 1000 miles on the clock. About 4 times over the past week, I've had a strong burning smell coming through the interior vents. On one occasion it was on a steep uphill start and I thought it was the clutch ( i'm still getting used to the long clutch travel!). But on at least 2 other occasions it's just been high revs on a nominal incline and i'm pretty sure then that my clutch control was fine. Any thoughts what the smell could be? Diesel?