Porsche is readying an even hotter 718 Cayman to sit above the GT4, with what appears to be a GT4 RS snapped during testing.
The GT4 was launched in July this year, and has already won plaudits for its balanced handling, raucous engine and manual gearshift. But for some that won't be enough. That's where the RS comes in.
Compared to the already pumped-up GT4, the RS carries even more aggression. The bonnet looks to be carbon-fibre, and houses two NACA ducts like that of the 911 GT3 RS with Weissach Pack.
There are also vents behind the driver and passenger windows, presumably to feed more air to the mid-mounted engine, while the low-set air intakes also appear to be slightly larger.
But perhaps the biggest change is the rear wing. Just look at the rear wing. Although it's unlikely to carry over to production in that form, it's safe to assume the RS will get a taller, more aggressively raked rear wing than the regular GT4.
The rear diffuser and exhaust system appears to carry over from the GT4, while the wheels and brakes are likely to be larger, wider and lighter than those of the GT4.
Expect to see a more powerful take on the naturally-aspirated flat-six engine from the GT4. It's offered with a six-speed manual or seven-speed PDK transmission, but we'd suggest the RS might be PDK-only, given that's the direction Porsche has taken with the 911.
Given the long development period for the regular GT4, we'd suggest the RS won't be revealed for a while – the end of 2020 shapes as one potential marker.