So I really got into Initial D again a few months ago. I thought it'd be fun to see what the voice actors from the show have done in toku.
Miki Shinichiro: Fujiwara Takumi was Sieg on Den-O
Yao Kazuki: Iketani was Ninjaman on Kakuranger and Dr. Z on Akibaranger's first season.
Iwata Mitsuo: Itsuki was Bebaboo on Gokaiger and Ayakashi Gizarai on Shinkenger. If you watched GaoGaiGar, he also did Mic Sounders 13's voice.
Seki Tomokazu: Takahashi Keisuke was Bibidebi from MegaRangers aaaand a bunch of other stuff. More recently he's been the voice of the Gokaiger items as well as random voices on the AkibaRangers Season Tsuu.
Hiyama Nobuyuki: Nakazato Takeshi was Tachibana on Fourze. Plus he's done a lot of other rad anime/toku voices.
Fujiwara Keiji: Shouji Shingo was... Chida Nick? What?
Anyway, you can see the full list for the first season here.