It hasn't yet been verified by Guinness World Records, but the Koenigsegg Agera RS is now the fastest production car in the world. It clocked a two-way average speed of 277.9mph across an 11 mile stretch of Nevada highway on November 4, claiming a raft of other titles in the process, including 0-400kmph in 33.29 seconds. The Agera RS's top speed on one run hit a staggering 284.6mph according to the manufacturer.