A 1959 Ferrari 250 GT Series I Cabriolet made $5.6m at Gooding & Company's Pebble Beach auction.
The lot is the last of only 40 ever built and features the distinctive variations in coachwork and materials that appear on the later models.
It was manufactured Pininfarina's custom workshop in Cambiano, Italy - meaning each model differs slightly from the other.
There were a number of major Ferrari sales over the weekend including a 1961 250 GT SWB California Spider, Steve McQueen's 275 GTB/4 and a 1962 Ferrari 250 GTO Berlinetta.
A 1955 Aston Martin DB3S realised $5.5m.
The car was designed as a replacement for Aston Martin's first race car, the DB3 - which proved too heavy to be competitive on the track.
It was built after William Watson, assistant to chief designer Eberan Eberhorst, managed to find ways to fix the car's weight problem.
The DB3S went on to win a string of races across the UK. Only 20 customer versions were ever made, with this example owned by the owners of an Aston Martin parts dealership.
We have this incredible racing jacket owned by actor and racing driver Paul Newman.
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