Reliability of electronic components in space
Tesla/SpaceX had probably removed the battery pack, electrolytic capacitors, other parts that aren't compatible with vacuum and don't die gracefully.

Your question are asked a lot by people who build CubeSats.  A lot of them are build with automotive, commercial, industrial components, because CubeSat budgets can't afford the officially space rated parts.

In grad school, I've worked with a team which have designed, built and launched a CubeSat.  What little I know about vacuum compatibility comes from that project.


  Would electrolytic capacitors lose their electrolyte and dry up?


Electrolytic capacitors outgas in vacuum, so they are avoided in the space hardware.  Tantalum capacitors are alright.


  Would LiIon batteries' pressure release safety valves pop?


Run off the mill cells outgas too. 


  Would chips popcorn due to moisture evaporating in vacuum?


That's not a problem.  There's not enough moisture to cause trouble.  


  Obviously, air-cooling of electronics would no longer work.


Spcecraft typically rely on conducted and radiated cooling.  Convective cooling is rare, with the exception of heat pipes.


  Radiation would zap CPUs and RAM.


It can.  There are various techniques for radiation hardening.