Holden builds a drop-top Monaro, but it won’t make it to production Look Ma, no roof: The Monaro convertible is a one-off engineering test vehicle. By BRUCE NEWTON 20 May 2004 YES, your eyes do not deceive you. That is a Holden Monaro convertible. Holden rolled the drop-top Monaro out at a function to show off its family of concepts today, and ‘Project Marilyn’ was the surprise guest. But before you rush off down to your local Holden dealer with the deposit money slow down, Marilyn is a one-off with no prospects for production. Instead, a production Monaro convertible will have to wait until after the all-new VE generation Commodore is rolled out on its highly flexible Zeta architecture in the first half of 2006. Not that Holden has signed off a convertible for production post-2006 as yet. However, Pontiac – which takes the Monaro as a reborn GTO in the USA – is strongly pushing for such a car when the new generation arrives. Marilyn was built in Europe in 2002 and 2003 by the now defunct TWR Engineering and Edscha, the German company responsible for the Astra convertible roof system. It was commissioned by former Holden managing director Peter Hanenberger and engineering boss Tony Hyde to investigate whether a convertible program was possible. It’s no coincidence this car is left-hand drive (and a V8 auto) as North America would have been the destination for most of the production run. However, the business case numbers did not stack up and the project was abandoned. “For the time the V-car architecture has left the cost of doing the car just wasn’t worth it,” explained GM executive director Asia Pacific design Mike Simcoe. “If it had been at all possible and made economic sense General Motors would have taken it for sure.” Holden allowed the media brief and slow drives of the car after its reveal today, but apart from the novelty of driving a Holden and having wind in your hair it felt much like any V8 auto Monaro. Which is understandable considering the engineering brief was to remove the roof but try and retain as much of the existing Monaro character as possible. All new panel design for Marilyn include new A-pillar assemblies, structural sill sections, rear quarter body inner panels, a double skin rear seat bulkhead and trunk lid outer. Doors have been modified to take a frameless glass system. There are reinforcements on the underbody and mountings for a bolt-on cruciform structure to help optimise structural requirements. The concept of individual rear seats carried over to the new design. A rigid tonneau cover behind the rear seats had ‘pop off’ covers above two integrated rollover protection hoops. The new rear seats had height-adjustable head restraints and centre-positioned seat belts and the use of Saab-style integral belts for front seats was being investigated. A-pillar, header, rear quarter and inner rocker trim panels is new. The fully lined and insulated black canopy was designed as a six bow system to retain styling shape. Operation is fully automatic, with what Holden calls “competitive cycle time”. The one-touch button operation began a sequenced system to drop side glass, unlatch the roof header locking system, lift the rear of the hood, open the tonneau cover lid, fold the roof system into the storage area behind the rear seats, close the cover and raise the side glass. And its code name? That derives from the old-time Monaro owners’ habit of nicknaming their cars ‘Munros’. Marilyn Monroe … geddit.