One of the most exclusive Miura still in existence is the Miura P400 Roadster, which was presented on the 1968 Brussels Auto Show. Designed and built by Bertone as a concept prototype, this open version was not just a regular Lamborghini with the roof removed, unlike the 350 GTS presented by Touring a few years earlier, the Miura Roadster was almost completely redesigned, with excellent taste as always.
The complete rear section of the car was modified, the rear louvers covering the engine were removed, the tail lights changed and the exhaust pipes now went through the lower grill. Various small changes were made to the rear section of the original Miura, like lowering the roof line by 3 cm and changing the angle 'rake' of the windscreen. All this was necessary to eliminate undesired turbulence at 300 Km/h even without the roof, which was actually never even built in the end, the Miura Roadster didn't have a roof panel at all.
Also note the air intakes behind the side windows were larger compared to the factory built Miura to allow more fresh air to be pulled into the engine bay, while the 'built in' rear spoiler was also larger than normal on the Roadster ... in fact Bertone even went as far as strengthening the chassis of their Miura to counteract the fact there was no roof left to keep the car from flexing, as a matter of fact there were no side windows on the Miura Roadster either because the rake of the windshield was modified the original side windows could not be used.
The interior also had to be modified, mainly because the switches from the overhead console found inside the regular Miura had to be installed elsewhere inside the car (they would end up on the central console), and the Bertone steering wheel showed a great similarity with the one found inside the Marzal and the Espada prototype ... both built by Bertone too.
The car was finished in a bright-metallic azure blue shade, while the interior was upholstered in a magnolia (almost white) dye leather (just like on the first 350 GTV in fact). The impact this show prototype had in Brussels and later on in Geneva was massive, but this was to remain stricktly a one-off, many owners requested a Miura Roadster from the factory, but Automobili Lamborghini SpA never officially delivered a Miura Roadster or even made a replica, while as mentioned earlier Bertone had never built a top or side windows for this prototype.
The Miura Roadster became also known as the Miura Spider or Miura Spyder, but her official denomination was the Miura Roadster, the original car was sold to the ILZRO in 1969, the International Lead and Zinc Research Corporation, a company delivering various metals to the car industry like aluminum, zinc and different alloys.
The ILZRO decided to buy a Miura some time earlier to reconstruct using their own metals and alloys to showcase their technology on various auto shows worldwide, but Lamborghini declined their request for a production Miura ... however with the Miura Roadster they had an oportunity of a lifetime ... this wasn't a production car, so together with Bertone and Lamborghini the ILZRO was able to do just about anything they wanted.
Chassis number 3498 was completely disassembled the moment it arrived in New York, all possible parts were changed into zinc-plated, chrome-plated, polished or re-manufactured using some metal (like lead!) made or distributed by the ILZRO, some of these items included the carburettor bodies, the carburettors stacks, engine covers, transmission covers, oil pump, filter housings, exhaust system, radiator, interior switches, the steering whee, the wheels themselves and both front and rear bumpers.
These modifications were all directed by John Foster, who was actually a designer for Ford. But the result was rather special, the Miura Roadster was converted into the Zn75, an ILZRO show car ... a mere Miura replica almost, she looked like a Miura, but she was totally different ... even in her exterior shade.
Bertone usually used bright colors and contrasting black detail work like as seen on the original Miura Roadster prototype, but the Zn75 featured chrome details and was finished in a metallic green sprayed over a black metallic base giving a strange dark green pearl like color (iridescent gold-green), with a contrasting brown leather upholstery it looked totally different from most Lamborghini Miura.
The name also changed, now into the 'Zn75', a name taken from the periodic table of metals used for this modification. The Zn75 first appeared in May 1969 after which she was flown all over the world to various Auto Show and shown to automotive companies worldwide, always attracting a lot of attention, when her job was over, the Miura Zn75 was auctioned off to S.F. Radtke, the Executive Vice President of the Ilzro at that time.
In late 1980 the Miura Zn75 was completely refurbished by Synthetex Inc. and valued at $186,000 when Mr Radtke donated the car to the Brookline Museum of Transportation in Massachusets, U.S.A. in February 1981. The Miura was then shown in this museum for a long time were it was for sale at one time for only $ 50,000, later it was restored for the museum by J. Geils from KTR Engineering who was actually on the board at the museum.
After the restoration the car was sold at an unknown auction for a rumored $200,000. Later this rare Miura was auctioned again and bought by David Joliffe of the UK based Portman group, who intended to start a Lamborghini museum featuring this very unique Miura, however the Miura Zn75 was subsequently sold to a Japanese collector, who sold it again to an owner in France before she went to the United States.
The original Miura Zn75 changed hands several times over the last few years before it ended up in the United States, owned by a New York based real estate developer, Adam Gordon who decided to have the car restored to the 1968 Brussels Salon original by the well known Miura restoration specialist Gary Bobileff starting in 2006.
The total restoration of this one of a kind Lamborghini would take about two years before the Miura Roadster would once again be shown in her original 1968 livery at the 2008 Pebble Beach Concours d'Elegance, where she took second place and was driven onto the stage by none other than Valentino Balboni ... in 40 years the Lamborghini Miura Roadster had covered only 7,444 km in total.
In late 2008 the unique Miura Roadster was offered for sale by the Kidston Auction house, no price was mentioned, but with this being the most important Miura in existance it might even be the most important Lamborghini ever next to the 350GTV prototype ... being both a Lamborghini factory and a Bertone concept show car, and to really make it even more interesting all the ILZRO Zn75 parts had been meticulously retained ... you could even build a second Miura Zn75 next to this original Miura Roadster if you wanted.
In 2013 CNN had this very special Lamborghini valued by Hagerty Insurance ... they came up with a value between $8,000,000 and $10,000,000 making her the most valuable Lamborghini ever, Hagerty Insurance valued the 350GTV at 'only' $3,500,000 to $5,000,000.
As usual such a one of a kind prototype had several Miura owner request a Roadster from the factory, but they made no intentions of actually producing an open-top Miura, be it because it would be too expensive to make it road worthy or the fact the removal of the roof caused the body to flex ... bottom line is the factory refused every request. However some owners took their original Miura to a workshop and had it modified into a Roadster replica by just removing the roof section above the seats.
As far as we know none of these Roadster replicas had the modified rake on the windshield, nor the special, larger air intakes on the side or new engine cover, one of the more famous replica is a white Miura transformed by Herbert Hahne, the German Lamborghini importer, this one also featured wider wheel rims and additional bodywork changes making it look like a Jota Roadster.
Later on this car was repainted in silver metallic and the deep front spoiler and large rear wing were removed before the French owner had her repainted again in a bright green shade ... note that this Miura did have a roof that could be mounted back in place, unlike the real Miura Roadster ... still only one Miura Roadster exists, and all the replicas probably only lower the value of the original Miura on which they are built.
The LamboCARS.com extensive specifications chart on Miura Roadster or Zn75 ...