I have now done about 600 miles since the first service at 600 miles. When I got it back from the first service the oil level was spot on the upper mark in the window, it has now dropped to be almost in the middle of the two marks (closer to the upper mark but I can clearly see that the oil level has dropped). Is this normal after just 600 miles? No signs of leaks whatsoever, so I guess it has burned up the oil. Anyone else have the same experience?