I stopped watching around #5. After watching this trailer, we're supposed to expect Han came back from the dead and Dom & Mia have a secret brother (where family is everything), that's never been mentioned once. W/Dom's background and them losing their dad, they definitely would have mentioned a brother in the story.
Besides all the unrealistic shit they do now, we're also supposed to assume that Dom has learned tactical defenses (where he reverses the grip on the pistol from Cena in the trailer).
Well, since you can't see Cena, maybe that's why we've never seen him for all these years, and it does make sense after all... 