To improve aerodynamics, the Roadster's roll hoop was lower than a Berlinetta's, Bertone also reinforcing the box section side members and roll bar to compensate for the lack of a roof. Finished in a gorgeous light metallic blue over magnolia leather with red carpeting, the Roadster attracted masses of attention wherever it was displayed but there was no capital to invest in another model and it unfortunately remained a one-off. However, 3498's story did not end there as later on in 1968 it was sold to the International Lead Zinc Research Organization (ILZRO). A promotional alliance of lead and zinc producers, ILZRO were looking for a high performance vehicle on which to showcase automotive uses for zinc and lead-based materials. They purchased 3498 and together with Bertone and Lamborghini, began a $200,000 makeover. This included a colour change to distinctive metallic golden green over a black base, the interior being re-trimmed in tan throughout. There were also a multitude of chromium-plated cast-zinc details like the wheelarch lips, bumpers, headlight surrounds and wheels, lead-alloy solder being used to smooth the body panels and zinc extrusions created for the sill mouldings. Many engine and transmission components were also lead or zinc-based including the exhaust system, carburettors, velocity stacks, radiator and both valve and transmission covers.

The original five-hole knock-off wheels were zinc-coated and painted while inside was lead-coated vinyl sound deadening and a zinc-plated steering wheel. Another big success in the publicity stakes, the refurbished car was known as ZN75. After 3498's second career had come to an end it was purchased by ILZRO's executive vice president, Shrade Radtke, who had managed the project throughout. He kept it until 1981, subsequently donating it to the Brookline Museum of Transport where it languished for many years. Now fully restored after being part of several top collections, the Miura Roadster is undoubtedly one of Lamborghini's most iconic vehicles.