Why are so many automakers dropping manual transmissions from their lineups? It turns out, they it is the expensive software to blame. While the transmissions may be simple and cheap to manufacture, the integration cost is sky high.

Total recalibration is required for a new car's computer systems to accept a three pedal gearbox. According to an industry insider:
Well, I can offer you some insight from my experience fighting for this from the inside of an OEM.

To develop, test, homologate, and certify an MTX [manual transmission - Ed.] variant of a vehicle platform is very costly. Probably more costly than the borderline MTX enthusiast might be willing to pay. It's not just the hardware which can get costly for a well synthesized box - It's the software. Whether we like it or not, software drives modern day cars. Engine, Transmission, and ESP/ABS/TCS systems all run on software. Sure, the base software for the control systems can be carried over, but the calibration for these systems is not trivial by any means, and requires significant man-years of development and several prototype test properties in multiple environments to develop, test, and certify performance and safety.

I knew a seasoned vehicle calibrator in the company, and he showed me a graph with an exponential curve fit through several data points. The X-axis was vehicle model year. The Y-axis was the number of calibration set points required for _just_ the engine calibration. In the 1980's it was up to 10. By the late 1990's it was in the 10,000's and the trend was climbing steeply. This didn't even consider yet the ESP/ABS/TCS systems which have also grown in complexity over the past decade. Add several tens of thousands more calibration points for them.

Most of the auto manufacturers do a 'value added' calculation to assess vehicle program feasibility / profitability. Unfortunately, when you consider the cost of the per-vehicle parts and development/test/homologation/certification amortized over the volume of a low take-rate option like MTX, it doesn't paint a good picture.

I fought long and hard for enthusiast oriented content during my career there, only to find that it was difficult to (believe it or not) get some product planners to appreciate the importance of the enthusiast market since enthusiasts serve as taste makers for the main stream.

So, all of you MTX fan boys and girls out there, keep buying new cars with MTX's. That's the only way to ensure that product planners can justify this kind of content. When the take-rates fall below 5%, it becomes a tough sell.