Tanahashi joined Toyota Motor Corporation in 1978 as a chassis engineer, and has since worked in new vehicle design for over 30 years.

[1] In December 1982 Tanahashi filed for his first U.S. patent, regarding the "upper support structure for front wheel suspension of automobile", which was granted in 1984.

[1] The supercar design program opted for a front mid-engine configuration, an approach Tanahashi favored for its combination of dynamics and safety.

[3] The vehicle development process was unprecedented in the company's history, exceeding the previous Toyota Supra in performance class, and requiring new engine, cooling, clutch technologies.

[3] Following the completion of the LFA design program, Tanahashi remained at his current position within the Lexus Development Center.