I think Stranger 355 nailed it. With more Gallardos made than Vipers, what constitutes rarity has to be based on a comparison of similar items. Ferrari builds more cars than Viper does per year, along with Lamborghini, Porsche, Corvette, etc., so in comparison one would have to state we own a rare machine.
With 507 done in 2010, and fifty of those were race cars ( ACR-Xs ) , I think we would be hard pressed to find many other well known supercars in that league of 457 for the street.
With 507 done in 2010, and fifty of those were race cars ( ACR-Xs ) , I think we would be hard pressed to find many other well known supercars in that league of 457 for the street.