A deleted scene of Spike telling Spitfire, Rainbow Dash and even Windy Whistles about how he plans on joining the wonderbolts. That is IF he had his wings at this time around.
But luckily, he DOES have wings now.
And Windy Whistles just HAS to hear about it too. As he IS a friend of her daughter. And she just wants to see Spike succeed in becoming a Wonderbolt one day. She may not be his mother. But she can still determined for someone who is a friend Rainbow Dash.