Bad idea.

First of all, I can't understand a word the dude says.

Second of all, I'm going to rather intolerant of the "how many roads must a man…." and "no direction home" quips.

But whatever.

That said, here's a partial list of celebrity GPS voices already available: Mr. T, Kim Cattrall, Dennis Hopper, Burt Reynolds, Gary Busey, Curt Schilling, and William Daniels (as the voice of KITT in the Knight Rider).