Hello,
I have experience developing automobile applications for embedding systems. I have developed embedded fuel analyzers and fuel volume checkers for covert enforcement, with these systems embedded into the trunks of automobiles. The systems were designed for -30C to 75C environmental operations and the controls built as IP65 modules. I developed custom environmental controls and thermoelectric modules to control the temperature of the sensitive instrumentation while the main control PCBs were designed for -40 to 125C operation and left in separate IP65 enclosures. Custom SEPIC power supplies were designed to handle the car's varying voltage, and full power protections (undervoltage, overvoltage, reversal, overcurrent, load dumps) were integrated into the system.
Systems were shown at PITCON in 2008 and JAIMA 2008, and several systems have operated for years without service. Later versions also incorporated Blutooth communications to eliminate wires from the passenger compartment to the to concealed systems.
The -45C will be very challenging, but should be able to be handled with good insulated enclosures and thermal controls. Military-grade components can also be specified that can cover from -55C operation, but the cost would be something to evaluate as a whole.
I can also provide fully assembled and tested boards and enclosure design (AutoCAD).
If this seems like the experience you need, please contact me.
Best regards,
Stuart Borden.