Everything's better with a Hummer

One long and sunny day, Celestia was just lying in bed, having just woken up. Today she had surprisingly little on her schedule, so she just decided to lay in bed. Celestia could feel the cool breeze winding in through the open window, the slightly firm mattress she was lying on, the soft sound of a bustling city far below, and a low, deep hum in the distance. Blink. She opened her eyes immediately. That last one seemed out of place. Preparing herself for an unknown adversary, she stood near the door. After about a minute, she felt the floor beneath her hooves rumble. The now roaring growl, the shaking sound and blaring horn only served to further the tension in the room. The air hung heavy with tense silence, anticipation apparent. Celestia was not ready for this.

Seconds later, the door shook. Princess Celestia was just about to fire up her horn when she was impacted by an unknown force. Boom! It felt like she was hit by a stampede. Everything hurt, and that's when she heard the loud shrieking. The loud, familiar shrieking... that was her sister! She just barely peeled herself off of whatever had just hit her when she heard it.

" Aahhh! That was the most fun we've had in eons!" That was Luna. What is going on?

" Oh my Celestia, that was amazing! It almost holds up to flying through the clouds!" And now she was hearing Rainbow Dash, for whatever reason. Did the impact knock her brain out her head?