Well, you don't necessarily need to have motion blur done to have the wheels blurred. Sure the wheels wouldn't be (very) blurry if you would use fast shutter speed setting when taking a photo in real life, but since the water spray is so misty and the picture is that dark I think slow shutter speed would have been used and therefore the wheels should be blurry.
If a car is in motion you won't be able to get that sharp picture of the wheels, they should be atleast a littlebit blurry.
I hope that made any sense.