This story is a sequel to The Shy Driver
Twilight Sparkle successfully performs a portal spell along with a crystal mirror portal in the Friendship Castle, connecting it to Justin Davis's portal on Earth. After some hum and ho, Fluttershy decides to invite her friends to meet Justin and show them her car. Things take a wrong turn when Pinkie Pie lets her tongue slip, and word gets out about the top-secret portal. It doesn't help that Justin finds out that his methods of keeping the portal's functions and development stage logs are under security and secrecy that even he finds hard to decode.
Rated E this time, although there does exist some mild violence.
2019 DISCLAIMER: This story was started off too eager and delved into too complex and far-reaching of a conflict for it to continue on with the other ideas that came up at the same time frame; thus it was cancelled. Looking back now, it's rather good, but I could've made a much better choice with many of the details.