Ok, I totally agree with ireckon, the dude was probably driving like a freaking monkeyhead. You live with the consequences of your choices, drive like a moron, you may die.
But as to the "living will" - think power of attorney instead.

"I hereby grant a limited power of attorney to ... in order that he/she may be able to access any and all of my records to include but not limited to ..." Any semi-competent para-legal should be able to knock one out on in a matter of minutes.

BTW, should you turn up dead, then your will kicks in and that POA is null and void. The POA only allows someone to do what you could do in the same circumstances, but if you are dead ... well you get the point.