Not to mention the SPD Red Ranger's entrance, one word and you know exactly who he is.
Pretty much all of Bridge's lines when the past Rangers formally introduce themselves to the Overdrive team.
Will: You've all been Rangers before.
Bridge: Well, except for me. See, I'm not a Ranger yet, but I will be. In the future, I'm going to be the Green Ranger, and then I'm going to be the Blue Ranger.
Rose: But you're wearing Red?
Bridge: Oh, yeah, well...long story short, our mentor, who's a dog...(Adam then gives Bridge a WTF look, coming from the same guy that had a giant, floating head as a mentor.)...got promoted to head of SPD, which used to be run by a bird, but he retired and went down to Miami, and then Sky got promoted, and then I got promoted, and that's why I'm the Red Ranger...or rather will be.
Dax: Makes sense to me.
Adam sums up what every long time fan thought when they first watched Dino Thunder:
Kira: Dr. O would've loved to see that.
Adam: I still can't believe he's a doctor.
At the end of the second part, after the battle is won and the Rangers are hanging at the mansion, the writers managed to put in one last nod to SPD. Spencer walks in with a stack of toast for Bridge, and this exchange happens:
Bridge: Is it... *makes his little hand motion*
Spencer: ...The butter-est sir. *also does the little motion*
In one episode, Flurious says he has half a mind to turn Norg into a throw rug, and later says he has half a mind to shave him until he resembles a naked ice rat.
Norg: Half a mind... for a throw rug... half a mind, naked ice rat—Well, that only leaves one half left! Flurious: FIIIIIIIND MYYYYYY JEWWWWWWWWWWWELS!