A tonneau cover allows the cockpit to be covered when the car is parked with the hood down, keeping the interior dry and free from debris. For regular open-air use it is one of the most practical accessories on the car, and the range covers every Roadster variant from 1962 to 1980 in a choice of materials and two distinct styles. The tonneau is specific to the Roadster.
Full Tonneau Covers
A full tonneau cover fits over the complete cockpit opening, covering both driver and passenger sides. Full tonneaux are available in four materials and in versions for RHD and LHD, with or without headrests, and for chrome and rubber bumper cars, so all four variables should be confirmed before ordering. Club vinyl full tonneaux are available in black with a choice of contrasting colour bindings. OE quality vinyl follows the same specification but is available in a wider colour range in Superior Vinyl for black or Everflex for colours.
Double Duck offers two layers of automotive canvas with a rubberised waterproof membrane between them, giving a natural fabric appearance as a practical alternative to mohair. Mohair full tonneaux are the premium option, manufactured in three layers, an external weather-resistant outer, a central rubberised waterproof membrane, and an interior lining, in black or a wide colour range with contrasting binding options. On the MGC, the tonneau was colour-matched to the interior trim colour rather than the hood colour, a detail that is easy to get wrong when ordering a replacement.
Chrome bumper cars fitted with seat belts that attach to the rear panel will need two small holes pierced in the rear of the tonneau to allow the belt fixing bolts to pass through. This is a straightforward modification and does not affect the function or appearance of the cover.
Half Tonneau Covers
The half tonneau, also referred to as a hood cover, covers the passenger side of the cockpit only, attaching using the hood's own rear fixing points. It is available for folding frame cars only, as packaway frame cars from 1962 to 1970 cannot use a half tonneau because there is no folded hood frame to provide the fixing points when the hood is lowered. The half tonneau is therefore a 1963 onwards item in practice, when the grey deluxe folding frame became available, and is standard fitment territory for all black Michelotti frame cars from 1971 onwards. It provides a clean finished appearance when the hood is folded without the effort of fitting a full cover, and is the natural choice for owners who use the car regularly with the hood down.
All fixings are pre-fitted to the cover. Half tonneaux are available in Club vinyl, OE quality vinyl, Double Duck, mohair, and padded mohair, the padded version adding padding for a sleeker, more tailored appearance and supplied complete with all fittings.
Function and Fasteners
The tonneau attaches to the cockpit surround via press studs and Lift-the-Dot fasteners mounted on the body and windscreen frame. A zip or popper arrangement at the driver's position allows the car to be driven with the tonneau fitted and one seat exposed, a traditional British sports car touring style. The material should be pulled taut when fastened to prevent water pooling in the centre, which will eventually stretch the fabric and cause it to sag permanently. Press studs and Lift-the-Dot fasteners deteriorate over time, the studs lose their snap, the sockets corrode, and the Lift-the-Dot bases seize.
A full set of replacement fasteners is available for refurbishing the mounting points, and when fitting a new tonneau all fasteners should be checked and replaced as necessary, as a tonneau that pulls free from one corner in a gust of wind will flap against the paintwork and can damage the cockpit trim.