Fast friends: Dale Earnhardt Jr. and Matt Kenseth are rivals with vastly different images and backgrounds, but that doesn't stop them from hanging out together and admiring each other's work.

From the outside looking in, Matt Kenseth and Dale Earnhardt Jr. might seem to be NASCAR's odd couple.

But from the inside, nothing could be further from the truth.

Sure, compared with Earnhardt, NASCAR's resident rock star--shooting a music video one day and photographing the Dahm triplets for Playboy the next--Kenseth does seem like the mild-mannered guy next door.

That's only if your next-door neighbor has a gorgeous wife; a custom-built Harley, a gift from the factory, in the garage; Metallica blaring from the speakers, and a Winston Cup championship trophy sitting on the mantel.

It's enough to make a lot of guys jealous, even ...