The Onyx M3 has an exterior with a front bumper with a carbon fiber lip, rear bumper/diffuser in carbon fiber, side skirts, a carbon fiber bonnet, carbon fiber boot and a roof spoiler made also of carbon fiber. I suppose there will be a slight weight loss due to all that lightweight carbon fiber here and there.
The interior gets buffalo instead of normal cow. I suppose this is slightly harder wearing and still can be had with various color combinations. Since the exterior has a lot of carbon, the interior can be laid with a 12 piece carbon fiber panel kit that can come in various colors, from the usual grey black to orange and blue. Much like the onyx coffee table, very garish.
For those who are a little power hungry, Onyx mentions that the standard 414bhp can be upgraded to 621bhp but does not mention how they will go about trying to achieve this figure. One can assume that a supercharger or a turbocharger kit will be bolted on for this feat.
No prices have been released at this point of time. But since most of the car can be custom made to the likes of the customer the sky's the limit.