and as nick mackie reports, the system is giving china a high- speed lesson in finance. >> reporter: another must-have, made in china. over the past seven years, the country's largest high-speed train builder, c.s.r. sifang, has profited from foreign firms that swap key technology in exchange for market access. c.s.r. then digests the original tech, developing it further to produce new even faster trains which it fully claims as proprietary technology. chief engineer ding sansan explains. >> ( translated ): if we export the 160-miles-per-hour train, we have to cooperate with our technology transfer partner. but if we export our new- generation 240-miles-per-hour train, we can do it ourself because we have the independent intellectual property. >> reporter: c.s.r. is working with general motors to explore the u.s. market. it wants to build trains in the u.s. using chinese technology. china knows a thing or two about high-speed rail. in just four years, it's built a 5,000-mile-long high-speed grid, and by 2020, a further 10,000 miles of track will crisscross the country, with the state