Our spies first caught the next-gen Audi A4 back in December 2021 and have been sending us images of various prototypes ever since. All photos in the database show the estate, but this long-roof test vehicle is significantly more interesting. For starters, it's the S4 judging by the quad exhausts with cutouts in the rear bumper that don't quite match the tips. These go to show the hot Avant lacked some of the final bits, including the taillights.

Spotted in the Austrian Alps, the new Audi S4 Avant was riding low to the ground while trying to hide the sleek new door handle design. The tall tyre sidewall tells us the wheels were quite small for a performance version but will make way for a significantly larger set on the production model. A closer look reveals the centre caps have what we believe are sensors going inside the car where there's quite a lot of hardware on the passenger seat.

2024 Audi S4 first spy photos

Speaking of the interior, the new S4 will feature a heavily reworked dashboard with a wide digital screen. Because of the spy photo’s angle, we can't say for sure if the display is big enough to incorporate the infotainment as well to echo the recently facelifted BMW M340i Touring. It probably isn't, so the touchscreen should be neatly integrated into the centre console rather than sticking out as it does on the outgoing S4.

The flat-bottomed steering wheel appears to be borrowed from the Q4 E-Tron while the chunky gear lever of the automatic transmission has made way for a much smaller setup. The simplicity of the door card is another sign we're dealing with an early prototype as it looks rather cheap and certainly not suitable for a luxury car. Elsewhere, the start/stop button seems to be roughly in the same place while those red buttons/switches are for emergencies to kill off the car's electric system in case of fire.

With Audi announcing it will launch its final ICE-powered new car in 2025, the S4 Avant will certainly be the last of its kind with a petrol mill. One question arises – will it keep the V6? With AMG downsizing the C43 Estate from six to four cylinders and throwing electrification into the mix, don't be too surprised if the peeps from Ingolstadt will do the same. For what it's worth, the RS4 Avant has already been confirmed to get PHEV power.

Audi will have the standard A4 Sedan and Avant on sale at some point in 2023, with the S and RS likely following in 2024.