It's the Audi A5 with a sunnier disposition — the new A5 Cabriolet, coming next year.

Closely followed by a new S5 Cabriolet flagship, the topless Audis are due in the UK early next year.

Chosen in preference to heavy and complex folding metal roof systems, the lightweight soft-top in the new A5 Cabriolet features a heated glass rear window, and in 15 seconds retracts into a compartment within the boot that automatically lowers to accommodate it. It raises again in 17 seconds, and can complete both operations at speeds of up to 50km/h.

When in place the three-layer roof very effectively insulates occupants from external noise, and for optimum refinement an optional acoustic hood is also available to reduce sound intrusion to virtually the same level as the A5 Coupe.

Roof up or down, the A5 Cabriolet can transport up to four adults in comfort thanks to its extended wheelbase, which helps to maximize cabin space. When the soft top is in place, luggage capacity is 380 litres, and in topless mode the roof stowage compartment only marginally reduces this to 320 litres. Thanks to the standard split/folding rear seat back a maximum capacity of 750 litres can be accessed if required.

Comfort is further addressed by new options such as a neck-level heating system built into the tops of the seat backs for cooler days and solar heat-reflecting leather upholstery that keeps seat surfaces cooler in direct sunlight.

In the UK the A5 Cabriolet will launch with a choice of three directly injected engines: the latest turbo charged 2.0-litre TFSI petrol in 155kW form, the 3.2-litre naturally aspirated V6 FSI petrol with 195kW and the 3.0-litre V6 TDI with 176kW. 2.0-litre TFSI and 3.2-litre FSI units are initially offered in conjunction with front-wheel-drive, while the 3.0-litre TDI is linked exclusively to the latest generation quattro four-wheel-drive system.

A six-speed manual transmission carries engine power to the wheels in 2.0 TFSI models, while 3.2 FSI and 3.0 TDI versions feature two automatics — the multitronic continuously variable transmission in the 3.2 FSI and the new seven speed S tronic twin-clutch gearbox, developed specifically for longitudinal ‘north-south’ engine installations, in the 3.0 TDI quattro. This all-new transmission will also be a standard feature of the S5 Cabriolet.

The sports differential enables the quattro system to not only transfer torque between the front and rear axles to counter traction losses, but also between the rear wheels. When the steering wheel is turned or the car accelerated in a corner, power is redirected in a controlled manner to the outer rear wheel, literally pushing the car through the corner. The driver benefits from reduced steering effort and a feeling of even greater adjustability and control.

At the top of the range the S5 will ride lower than standard versions on specially tailored ‘S’ sports suspension and 19-inch ‘S’ design alloy wheels. Aluminium-look door mirrors, Xenon plus headlights with LED daytime running lights, rear LED lamps, special ‘S’ front and rear styling treatments and black painted brake callipers bearing the S5 logo will also be distinguishing features.

The S5 adopts the very latest supercharged V6 TFSI engine, which produces 245kW, giving 5.6-second 0-100km/h potential. The S tronic twin-clutch transmission and quattro four-wheel-drive are standard features, the latter offering the option of the sports differential.