Final driving impressions: when I discovered the Sport mode on the suspension, I got a lot happier. I'm a purist and like as little electronic buffering between me and the road as possible. But this Cayenne in Sport mode at 120 mph was unbelievable. I could feel each wheel independently dealing with road imperfections and felt incredibly confident.

Except when I saw the fuel level dropping like the big glass ball on New Year's Eve and wondered if we should slow down on the off chance we might make it to the next cluster of old abandoned buildings that used to be a town and discover, improbably, that there was actually a working gas pump with 91 octane.

Should we slow down to 55 and conserve fuel?

No frickin' way!!! People, this is a Porsche! Let 'er rip! Thanks, GM! Great trip!