Adblue is in the back on a Mercedes. We saw it at the auto show a couple weeks ago. BMW has their urea up front near the radiator. Check your manual. I just bought a 35d last week. I have about 600 miles on it and the mileage is 25mpg. Took a test drive at the dealer. Yes, it has decent acceleration. Yes, when it's cold you notice a little vibration which smoothes out as soon as you drive it and it warms up a bit. I'm really liking this vehicle!