trevj wrote:I don't work in the car industry, but some sort of physical damping/shock absorbing would reduce the severity of vibrations. Sprung standoffs inside a sturdy cage suspended/tethered using multiple extensible wires inside a suitably sized void?
This is a good suggestion and I believe it'll help with very small and relatively weak soldering joints such as BGA. Miscellaneous car electronics such as car radios have absolutely enormous soldering joints. The image below is a popular TDA7850 development board (though it's also popular with hobbyists who wish to have a cheap high-powered amp but don't want the difficult hassle of a gain clone). If I'd place my raspberry pi inside a car as a car computer or data logger, I'd probably use some antistatic polystyrene foam around it. I'm sure any other soft non-conductive material would be fine for the purpose. I'm not specialized into the effects of electrostatic discharge, though it's probably not very good for electronics
I'm not entirely sure why BGA would be more susceptible to micro-fracture than regular soldering joints, though there's an entire industry specialized into BGA inspection tools. Then again, if you consider the BCM2835 has 299 BGA soldering joints on the bottom side (let alone another circa 150 between bcm2835 and the ram), it is not difficult to imagine that a damaged joint will contribute to the malfunctioning of the device. The connectors and BGA soldering joints are certainly things that'd be the first to fail on the raspberry pi when no overvoltage is set for extreme overclocking. All in all, the BGA soldering shouldn't be an issue in environments with no extreme temperature fluctuations like a car.
Edit: I now see the picture is actually a TDA7384. It's a lower-end version of the 7850 in the same package (flexiwatt25) and 100% pin compatible. It's totally off-topic to say this, but if you have a really cheap car radio with a tda7384 in it, you can upgrade it to almost double its output power and quality by soldering on the tda7850. The chip itself is like 6-10 dollars each on ebay, and it'll last a lifetime. The tda7850 is respected as a higher-end chip-amp and it can certainly stand its place as a class AB mosfet amp requiring just a single +12v and 0v input.