The cosmic radiation that reaches Earth's surface consists mainly of particles that cannot be stopped by thin shields (e.g. muons or other particles with very high energies), otherwise they would not have passed through the atmosphere.

So shielding is not a solution that can be applied in a vehicle. You need something like an underground bunker to be sure that no cosmic radiation can penetrate it.

The only reason that makes rare the events caused by cosmic radiation is that if those particles can pass through shields that means that in most cases they will also pass through the electronic devices without being absorbed and causing malfunction.