[MayeulC]

> current won't flow through your hand

Of course not, I didn't mean to imply that.

> if the ring itself touches [the car frame]

That's what I meant.

> 12V is too low to pass your skin with a significant current

Now of course the human body has a complex impedance, with cell membranes acting as capacitors: higher frequencies let more current flow. And that also depends on how much skin there is (single finger vs arm to foot), if it is wet, etc. I remember trying a (discharged) 9 V battery on my tongue as a kid... that was literally quite a shock, even with continuous current.

In the end, I wouldn't bet that an electrocution is impossible using a mere 12V of electric potential.

[littlestymaar]

We weren't talking about electrocution here, but about heating a ring quickly enough to burn you, which requires a much higher amperage than what's needed to kill you.

Anyway, given that 12V is considered safety voltage for submerged swimming pool material in France, I'm pretty confident it is be extremely unlikely to kill anyone.