Just days later after Tesla's filling lawsuit, it also received one - from Magna, maker of the transmissions for Tesla's roadster. Tesla initially wanted to use X-trac's transmission, but Tesla evidently spec'ed out a two speed unit with no clutches. This design intent was to do clutch-less shifting and manage the torque output of the motor during the shifts, but unfortunately the rotational inertia of the motor made this plan unworkable as the torque output couldn't be changed fast enough. Tesla's incompetence for not being able to get their control strategy to work lead to contracting Magna to develop a dual clutch two speed gearbox. Unfortunately, Manga's design had durability issues. After months of developing transmission in-house, Tesla made ultimate decision to revise the motor for more power and go with a single speed unit for production. The vehicles running with the interim single speed gearbox are actually using the original X-Trac box with the lower gear locked out (for prototypes) or removed entirely (early production cars). But Manga never received payment for its work. Therefore Manga is suing Tesla Motors for $5,6 million payment…