The Stuttgart-based automaker was seen yet again at the Nurburgring with what looked to be a unique 911. According to our spies, Porsche was apparently testing a 911 GT3 that has no rear wing. This comes as a surprise as every previous 911 GT3 has a large rear wing that helps provide extra downforce during high speeds.

Spied: 'Wingless' Porsche 911 GT3 spotted at the Nurburgring

For all we know, this could become the basis of a special edition 911. Our insiders think this may be the rumored Sport Classic, a bespoke 991 GT3 that will pay tribute to cars of old. It will have the running gear and powertrain of the standard GT3, along with a retro-themed exterior.

Telltale signs that the car is indeed a 911 GT3 include its distnct front bumper and grill, matte-black finished alloy wheels and its unique rear valence and centrally-mounted exhaust pipes.

Rear quarter view of the wingless Porsche 911 GT3 prototype

Since it's highly likely based off the 2017 911 GT3, the purported Sport Classic prototype will most likely be powered by the new 4.0-liter naturally-aspirated flat-six. It produces 507 PS with 460 Nm of torque and can be connected to either a manual or PDK (dual-clutch) transmission.

A closer look at the rear of the wingless Porsche 911 GT3

There are no other details yet about the rumored 911 Sport Classic, except that this particular prototype could become a limited-run model much like the 911 R.