Future GPX Cyber Formula

I'll just keep this short. Both series deal with a young driver who drives an advanced racing car. With Speed Racer, it's the Mach 5 with it's gadgets. Future GPX Cyber Formula, it is Asurada, the most advanced computer enhanced race car. So as you can see, both are car racing animes that are 25 years apart. You could call the Mach 5 the grandfather of Asurada. 

Very similar racecars in physical design, as well as technical elements like turbo systems and on-board AI aides. Both involve an underdog getting involved in a futuristic racing circuit aiming for the top. 

A strong aspect of both anime is the dynamic between a machine, its operator and the team of mechanics that keep it running. There are a lot of similarities between the two with regards to how the characters surrounding the machine interact and how their relationships evolve while working together. Another thing these two anime share is a tendency to step away from the larger overarching storyline to focus in on the characters dealing with some slightly mundane problem. These episodes are great for character development and give a lot more depth to the worlds in which they're set. 

Both involve seemingly rookie drivers who turn out to be out of this world drivers. Future GPX involved a more high-tech car where as Initial D involves an older car. 

same racing theme... same set in the future... same kind of technology used in the car... apparently same story and love story between the character