Is this PHEV Mule the B10 RS 4 Avant?

Our spy photographers caught a very interesting B10 Audi A4 Avant test mule out testing. While the wheel size and prototype camo on the bodywork suggest something more mundane, the details of this car definitely have us wondering if it’s the next RS 4 Avant… and if the next RS 4 Avant is a plug-in hybrid?!?

So why do we think RS 4? Well, for starters it’s running registration plates beginning with HN. Audi models tend to run IN for Ingolstadt, but Audi Sport models tend to run HN for Heilbronn (or Neckarsulm). Next, it’s out testing with an RS 6 and the photographer who caught it reports that it had a great sound… albeit that sound could have been emanating from the RS 6 as well.

And, are there flares underneath the trippy vinyl graphics on the bodywork? It’s hard to tell, but maybe. An early drivetrain mule wouldn’t necessarily have to have production RS fenders even if this is an RS 4, though the wheels and tires do look admittedly small.

Other rumors about the next RS 4 have suggested it will be a plug-in hybrid boasting about 500 hp. That’s a figure Audi really needs to have to compete with the M3/M4 an AMG C63. On the mule, we think we see a charge port that would indicate a PHEV, though it’s hard to tell with the camo. Beyond that, it does have a small green label on the back window that says PHEV.

Check out the additional photos and decide for yourself. If Audi builds a PHEV RS-car, would you buy it? Should they bring an RS 4 Avant to North America?