Now,coming to the 5th most expensive car at auctions. It's the 1931 bugatti royale kellner coupe. 

This is the 5th of this kind.

1.Bricked up with 41.110 and 41.150 during World War II at the home of the Bugatti family in Ermenonville, to avoid being commandeered by the Nazis.

2.Sold together with 41.150 by L'Ebe Bugatti in the Summer of 1950 to American Le Mans racer Briggs Cunningham, in return for FR₣200000, ($571 US) plus a pair of new General Electric refrigerators, then unavailable in post-war France. Bear in mind that the French franc had been drastically devalued in the years immediately following the war. The refrigerators were included out of gratuity.

3.The car was rough but drive-able. Taking the refrigerators into account, he essentially paid about $600 per car. Restoration costs would bring the total cost up to about 1 million Francs, or $2,858 US, per car. The cars were delivered to the states in January 1951.

4.After closing his museum in 1986 in 1987 the car was sold direct from Briggs Cunningham's collection by Christie's for £5.5 million or $9.7 million U.S. at the Royal Albert Hall, to Swedish property tycoon Hans Thulin.

Cool!!!! when it comes to good old classic cars money does never count.This car cracked a huge amounts of $9.7Million.