As evident from these Automedia images, the 4C Spider features a fabric roof panel rather than a folding hardtop, and the canvas lid is believed to be a removable panel in lieu of an electrically operated unit, in the interests of keeping the car's mass as low as possible.
The 4C coupe tips the scales at a waif-like 895kg, and reports suggest the ragtop adds only 60kg to this figure.
As per the fixed-head 4C, the Spider will be propelled by a mid-mounted 1.75-litre turbocharged four-pot that ekes out 177kW, relayed to the rear wheels by a six-speed dual-clutch gearbox.
Given that the Spider is expected to be only marginally heavier than the coupe, expect the 0-100km/h split of 4.2sec and 250km/h top speed to be more or less unchanged.
Enthusiasts will be pleased to learn the Spider scores a new titanium/carbon Akrapovic exhaust that enables the driver to dial up or down the volume depending on the prevailing mood and occasion.
A further piece of good news is that the coupe's fussy looking headlight clusters will be replaced with more conventional clear-lens projector units – as evident from these pics.
As per the coupe, the Spider will be a low-volume proposition, with only around 3500 units expected to be produced each year, commanding a premium of 10 per cent or so over the hardtop.
The Spider isn't the only 4C derivative that's in the works, as also reportedly on the agenda is a high-performance version that could wear Alfa's iconic Quadrifoglio Verde (Green Cloverleaf) suffix.
Alfa Romeo CEO Harald Wester hinted as much in a recent interview, in which he revealed: "We are only at 134hp per litre [100kW/litre], so there is space. The stiffness [of the 4C's chassis] is very high. The first adjustment would be the brakes."
The 4C coupe also spearheads Alfa's return to the US after a hiatus of more than two decades, although it had to be substantially tweaked (via a revamped interior, reinforced suspension, different front and rear frames, plus the clear-lens headlights that will debut in Europe on the Spider) to make it suited to American tastes.