I once drove a Cobra replica that whispered two things: "We can catch that guy up ahead, no problem!", and "Whoops! You almost died there."
Usually my Passat TDI is pretty silent - German stoicism and all that. Still, I'd bet that once in a while it would like to tell me...
"I don't care if she is Italian and naked, stop riding that two-wheeled hussy and take ME on a weekend trip!"
I have to admit... one time the corvette said something besides “faster”. On the turnpike with the top down trying to see what the top end was. It said “ARE YOU CRAZY!!!!!” And it had to SHOUT it because there was a heck of a lot of wind noise.