hiroun156 posted this fantastic video about testing the Prince R380 on Youtube:
During its testing you can see it drives with an average of 250km/h on the big testing course. Not bad for a first attempt by Prince to beat the Porsche 906 on the Fuji Speedway with a mere 200hp engine! Not only did it beat the Porsches in 1966 but it set some new land speed records! Hayai!