What happens when lightning strikes a vehicle? The answer, gleaned from anecdotal observations, is all the way from "Nothing" to "Wow! What a mess . . . my car is a disaster."
Electrically speaking, at lightning's higher frequencies, currents are carried mostly on the outside of conducting objects. A thick copper wire or a hollow-wall metal pipe will carry most of the lightning on outer surfaces. This phenomenon is called "skin effect." The same holds true for lightning when it strikes metal vehicles: the outer surface carries most of the electricity. The persons inside this steel box can be likened to protected by a partial Faraday cage.
Some general safety issues vehicles and lightning: click here
Source: dailyfunmedia lightningsafety