“How much? That’s impossible to tell,” Nissan’s Kazuo Hioki laughs. TG has asked him to quantify the net worth of the cars stuffed inside a nondescript, secret warehouse in Zama, and he’s struggling to count.

It’s impossible, but you get some idea from just one of the astonishing machines on display. The R390 GT1 car that took part at Le Mans in 1998, for example, is estimated to be valued at well over £1 million. Another, the original Skyline GT-R, is worth a stratospheric amount too.

Zama of course, will ring a bell to anyone with a passing interest in Nissan’s history. It’s the heritage warehouse northwest of Yokohama in the Kanagawa prefecture that’s home to around 450 cars covering more than 80 years of Nissan’s road and racing heritage.

It’s not open to the public, but Nissan has granted Top Gear very special access. “It opened in 2010,” Hioki-san tells us. “Before this warehouse, all the cars were just stored in car parks and the like. Probably not the best conditions – out in the open air – so we first moved inside the building across the street, and then here.”

Photography: Rowan Horncastle