1967 Ferrari 275 GTB/4*S N.A.R.T. Spider by Scaglietti

The New York Times' Wheels blog has a really interesting story on a pair of Ferraris that are set to be auctioned off in Monterey during the Pebble Beach Concours d'Elegance. While the two cars are similar on the surface, their differing histories and Ferrari's attitude towards one of them has led to a sort of experimental auction process.

On the one hand, we have one of ten 1967 275 GTB/4 NART Spiders, in the classic Rosso Corsa and appearing at RM Auctions and seen above. On the other, we have a Fly Yellow version that started life as a 1965 275 GTB Coupe, and was converted into a NART Spider. Called a "cut" car, this particular replica is one of about 100 GTB Coupes that were converted into convertibles to satiate the climbing demand for ultra-rare Spiders.

This will mark one of the first times that an original NART Spider will go toe to toe with a replica of itself at auction, and will answer a number of questions about just how important provenance is in the collector car world. Head on over to The Times blog for the full story.