Ground strap

[DriveHard]

Nope, wouldn't work as a faraday cage.

Yes, yes it does...my family and I have been struck by lightening in our car and all were fine, including my 1 year old son in the back seat. My bride received a small burn mark where the seat belt anchor is located. It blew nearly all the interior trim panels off the car, but we were fine. I was able to re-start the car and drive to the ER to make sure my bride was ok. The only computer that was broken was the one to control the airbags.

If you don't believe me...

 

[another Todd]

I stand corrected. I have only ever heard of them used to block radio waves, but a faraday cage can block lightening as well...however, a faraday cage would not have large, non conducting openings such as the vehicles windows in it, so a vehicle is most certainly not a Faraday cage.

 

[VolvoZ]

Many decades ago, i had a 1976 Chevy Monte Carlo that at one point was having issues with the dashboard dimming intermittently and other funny electrical happenings. After a few days of dealing with that and some investigating, i recall reattaching one of those copper braided grounding straps from the engine to the firewall. That fixed the problem. One would think that with all the fasteners connecting the alternator to the engine, engine to the frame, frame to the body panels, body panels to the firewall, and on and on that you would not need a separate ground strap. Guess you do!