When you want to blend the character animation with mecanim, you need to make the animations separated by "concepts" this means that when there are several animations finished, it's easier to make a simple animation and blend it with the others. If you are using Maya Animation layers you can ensure that this animations will blend perfectly.
On the next video you can see the animations on the ugliest way you can see them: splited. The hair, the wheels, the hands...all it's in different frames and this allow us to blend it later with mecanim. Don't worry, later I'll show the end result and it's quite better.
