I have measured the ac magnetic fields in my V70's cabin and have decided to add a ground battery cable following the positive cable from the battery, under the seats and to a grounding spot in the engine near the battery jump-start terminal. Volvo said they don't know the AWG gauge of the present positive battery cable. I have measured its diameter and have compared it to some advertised on the WWW, but i am still (because of the various insulation thicknesses) not sure if it is AWG 2 or not. I will try calling some of the advertisers, but i thought i'd ask the V70 cognoscenti (whom i've come to quickly admire in these threads) if you know what gauge the cable is.