I own a 1999 BMW M3. I'm a retired computer programmer. I understand the hardware and software aspects of electronic systems.

The BMW I've owned since new. I've been through a number of parts includfing 3 ECUs. (engine control unit)

The ECUs malfunction and eventually fail in the vehcle due to environmental conditions.

The basic problem is the ECU circuit board is subject to the environment. Mine have been getting wet. When they get wet, the circuits are crossed on the main ECU circuit board. Sometimes, they will short out a circuit and actually stop the engine from running. Other times it might rev from 500 -2500 rpm. Other times it signals sensor failures in the wheel sensors.

Fact is the moisture on the circuit board can also act as a capacitor provide inaccurate signal reading and subsequently improper response from the ecu. Perhaps even initiate a signal when nothing is sending a signal.

Condensation, almost any potential source of moisture can affect the board directly because the boards are not hermetically sealed..

This sets up the system for various prblems due to cold weather, warm storage and vice versus.

There are a variety of control units in my BMW. Some are under the dash with lesser potential affect from the environment. However, many others are under the hood, like the ASC (automatic skid control) and the ABS pump and ABS controller. These devices control your brakes.

There are now more points of failure in the auto than thre is in an IBM computer room.

The ECU (and perhaps some some other modules) should be in a heremetically sealed box.

If not, even humidity will have an impact on the boards and theor operation.

Does the redundant aspects of the software support testing and analysis of potentially crossed signals. I don't think so.

Example: My BMW tells me when i lose a back license plate light, but doesn't tell me when my brake fluid indicator light is burnt out, so I will never know the level of the brake fluid until i can't stop. (this has actually happened to me)

Get engineers with real world experience and you'll get a safer more reliable product.