First off, there is electric field strength (ie high voltage) which, other than your ignition system is not present in your car with a 12 Volt system. Next there is magnetic field which is caused by high currents and to my knowledge not linked reliably to any health risk.

Look at it this way, you spend a few hours a week in your car 'near' a 20 amp line. If this is deadly how do prduction welders work all day for years beside a 250 amp stick and mig welder? What about a 25,000 amp resistance welder?

Loose sleep if you want to. To me this is stupid!