User blog comment:MiscellaneousSoup/Magic Carpet Ride/@comment-3347644-20110514035428/@comment-3347644-20110514040904

Not attempting to advocate a moment between Phineas and Isabella, but I'm presuming those choices can be ruled out. Any 'romance' shared by Ferb and Vanessa -- though endearing -- has been limited to an adolescent crush. Their relationship is not a prominent aspect of the series, as is Phineas and Isabella's. Hence, it's pretty unnecessary to display a moment as a 'magic carpet ride'. As Summer Belongs to You explored their relationship, though, Across the Second Dimension is a viable option. Coltrane has only been featured in a singular episode, and Stacy's relations would not advance the show in any manner.

I do like your suggestions, though. :)