Powertrain details for the next-generation Audi A4 remain a mystery. However, new spy shots of the A4 Avant capture the model with a charging port, hinting at the expected range of engines from the car. Sadly, Audi continues to hide the car under a layer of camouflage, hiding the rest of the design. The charging port is quite visible – a black plastic disc over the rear wheel well. Audi hides the fuel door on the other side, making the differences even more noticeable. Our spy photographer actually captured two different A4 Avant cars being tested in the snow. The second doesn't reveal the charging port to our camera, but sports high-voltage stickers on the front, back, and sides. 22 Photo While the photos provide more information about the A4, we still don't have the specifications. There have also been conflicting rumors about the model's direction, with some suggesting that the turbocharged 2.0-liter from the current generation car will be carried over to the new model with a few tweaks. However, others have suggested that Audi will be adding electric assist to the A4 lineup, which seems more likely after these new spy photos. The automaker confirmed in 2019 that the hotter RS4 Avant will receive a plug-in hybrid setup, but we don't know much about that. The A4 in the photo above is missing the RS model's signature oval exhaust pipe. We've also spied the mid-level S4 Avant, and it looks like Audi is keeping a 3.0-liter V6 under the hood. The more subtle wagon-style details are hidden by camouflage. The car will get a wider grille with a trapezoidal opening on the lower bumper. Both A4 Avants still use stand-in taillight units. The interior spyshot flaunts a dual-screen layout, with a narrow view behind the wheel for the driver and a larger one in the center of the dashboard for infotainment controls. We expect the next-gen A4 and S4 to debut next year, but those excited about the hotter RS variant will likely have to wait until 2024. Audi hasn't said when it plans to reveal the revamped model.