Rainbow Dash loved the WonderBolts so much that she drew herself as a one. She had a Soarin and Spitfire toy. She loved them and she slept with them every night.
She even had a picture of Spitfire saying on it in beautiful writing:
Always follow your dreams! - Spitfire~
Rainbow treasured it and loved it. She looked at the writing and letters lovingly.
One day when Dash was about five, she took part in a race to earn Flutter Shy's dignity.
She LOVED racing. She liked it. Alot! Then she was getting faster and faster. She was about to break the sound barrier!! Suddenly... BOOOOM!!!!! A fiery rainbow spread out all over Equestria! Ponies everywhere could see it. Rainbow zoomed ahead leaving the others behind in the dust. She did it. The sonic rainboom! The first pony EVER to do such a thing! She won the race and earned an amazing cutiemark. A cloud with a rainbow lightning coming out of it! The WonderBolts would let her in their team for sure!
She just had to grow up first...
Later on in Dash's teenage years she enters the best young fliers competition. The winner got to spend a day with the WonderBolts! Discouraged because of her friend, Rarity's wings she enters the arena. Rarity follows. The rest of her friends, Twilight Sparkle, Apple Jack, Pinkie Pie and Flutter Shy watched in horror as everything went wrong.
She flew higher into the skies to perform the Equestria famous sonic rainboom. Suddenly Rarity's wings evaporate into thin air.
Rarity falls and falls. The WonderBolts raced down to get the terrified Rarity. Unfortunately, her flailing legs kick the WanderBolts in the face, knocking them out.
This was the last straw. Rainbow Dash plumets to save her friend. Then she realises that she's about to break the sound barrier. Then finally... She'd done it! She had done the sonic rainboom! Catching Rarity and the WonderBolts, she performs a brilliant rainbow!
"I wish I met the WonderBolts when they were awake..." She murmurs sadly... Then someone tapped her on the shoulder. It was Spitfire, Soarin and the rest of the WonderBolts! "omigoshomigoshomigoshomigooooosh!!!!" she cries happily. Princess Celestia approaches the cyan and rainbow pony.
"May I announce that our best young flier is Ms. Rainbow Dash!" she shouts out to everypony in the stadium. They cheer loudly.
"Hey uh... Hi Rainbow Crash-"
"DASH!"
"Oh sorry... uh.. dash we have just come to congradulate you on winning." It's the ponies which insulted Flutter Shy.
"Yeah! Maybe you could teach us how you did that awesome sonic rainboom!" one of them said.
"Sorry boys!" Rainbow taunts. "But I've got plans!"
Arm in arm with Soarin and Spitfire she flew towards the setting sun.