Making entity with rider pushable.

Adding next code to onUpdate() helped me to make my wagons collide with each other, but only if they are empty. How do i make them collide with player inside?

//taket from boat class
if (!this.worldObj.isRemote)
        {
            List list = this.worldObj.getEntitiesWithinAABBExcludingEntity(this, this.boundingBox.expand(0.20000000298023224D, 0.0D, 0.20000000298023224D));
            if (list != null && !list.isEmpty()){
                for (int l = 0; l < list.size(); ++l){
                    Entity entity = (Entity)list.get(l);
                    if (entity != this.riddenByEntity && entity.canBePushed()){
                        entity.applyEntityCollision(this);
                        this.applyEntityCollision(entity); // line added by me
                    }
                }
            }
        }