True, maybe a little bit more openness would not hurt nobody. Probably would help people trust automakers more and not go nuts when a scandal goes live like the VW.
Never seen any banks open their strategy to the public after so many of them fucked us over a few years ago. It's not like I can copy their strategy and go make me another bank.

But going back to automotive, because that's what I do for a living. The process is quite strict and controlled. Efforts is done and periodic audit is done too to ensure adherence to ASPICE (http://vda-qmc.de/en/software-processes/automotive-spice/) and other regulations, including customer audits, which are tough. We do have internal processes, coding (and not only) methods, source control, configuration management (features, bug tracking) across all project and generic development base.

The basic workflow is follows a V-cycle path:

- receive requirements.

- requirements engineering, experts involved;

- test design based on requirements;

- internal design of whatever kind (models etc.);

- design reviews, simulations (if models), all kind of analysis;

- implementation (if not code generation);

- code reviews;

- static analysis ((pc-)lint, klocwork to name a few);

- module tests (unitary tests (ptu), tests on the HW with simulated signals - aka tetsbench tests);

- integration tests;

- system validation tests (requirements tests), hardware-in-the-loop tests, close loop tests;

- dependability tests run on the car.

In parallel the system is calibrated and calibrations are used during validations. For every version going into production (because some are just interim steps for validation purpose), there's a lot of testing going on on features already tested before.

SW execution is monitored by SW. The micro is monitored in some interesting ways and on top of that an IC is monitoring all the... other monitors. Lots of stuff is done to ensure RAM/ROM consistency, process execution monitoring, signal acquisition plausibility. Many inputs/executions diagnostics are requested by the laws, but a lot more are done for system robustness.
Not gonna talk about HW design and validations. They have their own set of regulations and standard tests to fulfill, which I don't know that good.

This is where the car maker takes over from the supplier and does their own set of tests (which I don't know in much detail):
- tens/hundreds of thousands of miles on a fleet of vehicles, recording all that happens and future analysis follows
- cold trip, hot trip plus various trips to test response to different altitudes, sea side effects etc.
- lots of garage testing
- regulations tests (the car must respect various regulations of the countries it targets... OBD regulations, CARB, EU stuff, etc.)

A lot of other tests are carried out in different phases of production. For example a special SW which runs on the production line is designed to test all circuitry one last time before flashing the real working SW.

Too many people have the impression this SW is build "on our knees" (an expression that sounds good in my native language), but this is far beyond that. The threat of car recalls (which is, in the end, charged to the supplier causing it, or the car maker if it is his fault) and fucking up all the profit is not stuff engineering plays with. There are over 1k engineers working on engine ECU R&D in various locations (from system design to SW and tests).