I think before opening you should hire the above retired engineer to do a transient non-linear structural dynamic analysis with modal analysis to ensure indicated drop did not induce any unwanted vibration, in addition to the shock pulses, that could have induced some fatigue on the PWB solder joints. Might also want to look at a thermal analysis of the thermal stresses inside the car that could have also reduced some life on said components. Could probably spend $2000-$20,000 on the analysis depending upon how much detail you want, parametric modeling, documentation, etc.
Or as GRJ indicates, take a risk that the shipping environment from overseas to your house might be worst case.
