Wirebox : how to have beans lazy loaded

Hi !

I have a CarService with a "load" function that returns an empty
CarBean by default. Using wirebox, I inject the result of a
MotorService.load() that returns a empty MotorBean into the new
CarBean (with property name="Motor" inject="id:...).

Now I would like to instantiate a populated CarBean (using
CarService.load(ID=xxx)) but instead of setting up the corresponding
MotorBean in the CarService.load method, I would like it to be
automaticaly setted only when I call the CarBean.getMotor() function.

If I'm right, this is a simple lazy load relationship but I can't find
how to do this.

Thanks for your help !