Wangan Midnight vs Initial D (Johnsonverse)

Before The Timeline/Plot Begins
As a fan of these 2 racing animes, this would be very difficult to make in real life. One anime takes place on windy mountain passes, while the other is on a massive interstate with speeds exceeding 300km/h/200mph. But if it were to happen, this is what I theorize the crossover would be like. This timeline has subtle plot points that include referrences to Dreaming Of Akina, a fan story about Bunta's background.

Announcement of the Manga/Anime Crossover
On July 2nd, 2007 is announced that a crossover was being planned, with a whole first stage being plotted out. The anime racing world was never so excited as it was that day.

Episode 1
Takumi gets a call from his father Bunta that his Subaru Impreza has a flat tire as he was driving on the Wangan to go see some old friends from his childhood. Takumi, naturally, brings his beloved AE86 with the pedal floored all the way, bringing the spare tire Bunta had left at the shop to make room for the tofu deliveries. As he approaches Tokyo, Takumi remembers he had been cautioned by his father about illegal racing at the Wangan, but he was not expecting what he would see as he started passing by Tokyo. Coming up fast in Takumi's rear view mirror were a impossibly fast Fairlady Z S30Z, which Takumi saw an insane aura coming off of, and a Porsche 911 Turbo 3.6 (964) whose driver also had a truly impressive, but slightly fainter Aura. "Those drivers are truly one with their car." Takumi observes as the pair zip past Takumi's AE86, that, even with it's AE101 (AE101 20V Silvertop) (Toyota’s TRD Group A engine, a version of 4AGEU), is only capable of around 200km/h. After zipping past the insanely fast cars stay in Takumi's sight for less than a half a second before vanishing from their sheer speed.

Takumi eventually locates Bunta and the Subaru and, while replacing the tire, asks him if those guys passed by him too. "Yeah, they were like a couple of flashes, and that was it. Truly insane people to do that on a busy interstate." Bunta states. "I could swear one was an old Fairlady Z." Takumi states. "Impossible, that car's from when I was a younger man and I can tell you that stock it only runs around 130 hp. It's max potential is around 300 hp as far as I know. That guy was going at least 300kmh. It's just not possible, plus that old body couldn't take that kind of force." with that Bunta finishes replacing the old tire with the new one, lights a smoke, says goodbye to Takumi, hops in the Subaru and takes off towards his destination. Takumi thinks about what he saw on the (now that he's going the proper speed limit) 3 hour drive all the way back to the Fujiwara Tofu Shop in Shibukawa.