Someone had the bright idea of converting a Lamborghini Diablo into a convertible model, this was however never a factory built Roadster. The looks of this specific car were much like the Diablo SE 30 Anniversary edition, but with five-spoke multi-piece wheels mounted with 18 inch tires. The interior was a leather upholstered one with standard seats.
It is very unlikely this was a real Lamborghini, I personally think it was just a replica, modified into a roadster after a roll-over accident, just like the Countach Roadster featured on this site.
If it was actually a real Lamborghini built Diablo SE30, it was a very bad idea to convert it into an open-top car, the SE30 was only built at 150 units, with only 25 for the United States, so I can't imagine this conversion will force the price up, just like with the Miura, some cars were converted into roadsters but they never did get accepted by the true Lamborghini lovers.
A visitor to this site has mailed me the origins of this special Diablo, actually it started life as a normal Diablo VT, Platinum Motors have built this 'special' from it, probably to be able to sell it at a higher price than normal, according to this mail they are also responsible for the Twin Turbo versions of the Diablo, I suppose this is the Diablo VTTT found on a different page.
During an interview with Stephan Winkelmann by Car and Driver the Lamborghini CEO confirmed a production run of 9 Veneno Roadster units.
(added on August 17. 2013)
Rumors state that the Lamborghini Reventon Roadster was recently unveiled at Sant'Agata during a VIP event.
(added on August 9. 2009)
Footage of the impressive show surrounding the official worldwide unveil of the Veneno Roadster on top of an aircraft carrier in Abu Dhabi
(added on December 2. 2013)
Rumor has it Lamborghini is doing some research to determine if a limited edition production run of a Veneno Roadster would be viable.
(added on August 5. 2013)
A lot of talk has been going round about the Lamborghini Aventador Roadster being ready for the unveil at the 2012 Geneva Auto Show.
(added on December 11. 2011)