Audi RS6 vs Mercedes-Benz C63

What's the difference?

When I say this is a rare review, I’m talking about the kind of rare that means you can’t even buy the car you’re reading about.

The 2026 Audi RS6 Avant GT you’re looking at in the pictures around this story is number 248 of 660. That’s six-hundred and sixty worldwide.

In Australia, there are only 22 RS6 GTs, and they’re all sold - at exorbitant prices, mind you, but we’ll get to that.

The RS6 GT is essentially a production version of the Audi RS6 GTO concept, built in 2020 and inspired by the Audi 90 quattro IMSA GTO race car, which means the RS6 GT carries a lot of ‘90 GTO’ in the way it looks. More on that shortly.

Aside from its extremely limited availability and its design package, there are some mechanical changes to increase the appeal of the RS6 GT, though whether any of its owners will put the on-road (or on-track) ability of this special wagon from Ingolstadt to the test remains to be seen.

A couple of days to live with one of the few RS6 GTs in Australia should reveal how special this car feels, and result in at least one example of the rarity being driven good and proper.

If you know the Mercedes-AMG C 63 S, you know it’s a hardcore V8 thumper with little in the way of bashfulness. It’s a brawler. A beast. 

Now there’s an even more eye-catching AMG C 63 S Coupe, which we’re testing here. It’s the Aero Edition - a collector’s version of the current-generation C 63 S Coupe with a bit more visual bling that also helps it stick to the road better.

It is a local area special edition, with only 63 examples to be sold across Australia and New Zealand. And if the rumours are true, the next-generation will see the V8 engine in danger of being axed in favour of a hybrid, high-performance four-cylinder version. Say it ain’t so! 

Well, if the CarsGuide crystal ball turns out to be right, maybe one of these C 63 S Aero Editions is worth getting in your garage quick-smart. Or is it? Let’s go through the criteria and see how it stacks up.