The series shows that Phil Coulson's personal car, Lola, can fly. In the S.H.I.E.L.D. comics, flying cars supplied by Stark Industries have been standard vehicles for the organization since 1967.
Several episodes from the first season establish the origins of several long-running Marvel characters. For example, Franklin Hall introduced in episode three, "The Asset", who becomes the supervillain, Graviton, and Donnie Gill in episode twelve, "Seeds", who becomes Blizzard, one of the foes of Iron Man.
The information given about San Juan, Puerto Rico, is accurate. Even the legend regarding "La Garita del Diablo" (The Devil's Sentry Box) is correct. Still today, no one dares to get inside of it, although it's closed to the public anyway. Also, the place marks one of the vertices of the Bermuda Triangle.
After the series wrapped, Chloe Bennet got a tattoo of a daisy on her arm to honor her character of Daisy Johnson.