We've already looked at the one-of-a-kind 1964 Shelby Cobra 427 Prototype and the exceptionally unique 1941 Chrysler Thunderbolt Concept Car set to feature at RM Auction's highly-awaited Automobiles of Arizona event in January.

But they are only two of a range of notable consignments which are guaranteed to make collectors' mouths water at the January 21-22 sale.

The 1930 Duesenberg Model J Arlington ($450k-650k)

Highlights among them will include a 1930 Duesenberg Model J Arlington Five Passenger Club Sedan offered without reserve (estimated at $450,000-650,000).

Meanwhile, a beautifully restored 1933 Rolls-Royce PII Continental 3-Position Drophead Coupe (s/n 74PY) with coachwork by J Gurney Nutting will also appear, estimated at $400,000-500,000.

A restored 1933 Rolls-Royce PII Continental 3-Position Drophead Coupe ($400-500k)

A former fixture in the esteemed John McMullen Collection, the 1913 Packard Model 1-38 Runabout - not the first Packard to sell this year - will also drive up to the auction block, at $400,000-500,000

Now in its 11th year, RM's Arizona event will present for the first time an additional opportunity to purchase important cars produced by British manufacturers - including the ultra-rare and legendary 1963 Aston Martin DB4 GT Superleggera - during an evening auction on January 21.

The 1913 Packard Model 1-38 Runabout ($400k-500k)

A preview of the 2010 line-up will be held January 21st from 9am to 4pm, followed by the British-themed Thursday night auction, billed The British are Coming!, starting at 6pm.

The auction action continues on Friday, January 22 at 11am. Admission is by catalog purchase only, which admits two.