The most expensive car in the world is the rolls-royce la rose noire droptail. Touted as the costliest car ever made at a staggering rs. Rolls-royce la rose noire droptail serves as the british luxury car maker’s tribute to automobile craftsmanship. The rarest vehicle in the world is arguably the 1955 mercedes-benz 300 slr uhlenhaut coupé. Only two were ever produced, and one sold for a record-breaking $142 million.