Counter point: the gearbox in the Turbo 99s & 900s is notorious for breaking because the construction of it was originally spec'd out for the torque of the non-turbo engine and Saab never revisited this when it put a turbocharger on the engine. So the gears can break under the additional torque.

Also one of the reasons, as I discovered, why the 900 is sadly not a good candidate for EV conversion. The transaxle would just break to pieces if you put the torque of an electric motor on there. Especially considering for a car like that you'd want something sporty.