Since the most important addition to the SLS is the body kit, we'll start with this first. The Widestar gets the usual front bumper/spoiler setup, rear bumper/diffuser setup, bootlid spoiler and only slightly wider rear wheel arches with optimized (and larger) air inlets and outlets. It isn't one of those really over the top, super wide body kits like we've seen on some tuned cars. It actually pretty subtle for a 'widebody' kit. Too subtle in my opinion.
Anyway, the front inlets and fender outlets are also aerodynamically tuned and tested at Brabus' wind tunnel facility to optimize airflow throughout the car. All of the components mentioned above are made from carbon fiber and customers can opt for a matte or glossy finish for the parts if they do not want to paint the add on parts. But do note that it is only wider at the rear wheel arches as the front fenders and arches are not extended. Only the front fender outlets seem to protrude more than the stock ones giving some illusion of a wider front end.
To complement the package even further Brabus gives the Widestar SLS an adjustable suspension that is driver controlled from inside the cabin. Aside from being 30mm lower, the suspension system allows the driver to increase or decrease the ride height as well as harden or soften the damping rates to make the car handle better when needed or ride better when the driver wants some comfort instead. The bespoke system was developed in collaboration with suspension specialists Bilstein. If the customer still feels that this isn't extreme enough, there is an option for stiffer anti roll bars front and rear.
To complement and to ensure that the rear wheel sit nicely under the wider arches the rear gets 21inch wheels running rubberband 295/25ZR21 series tires and the fronts get 20inch wheels with 275/30ZR20 tires. The wheels are Brabus specific Monoblock F Platinum Edition and must cost a bomb too. According to Brabus, the alloy wheels are lighter even though they are bigger than the stock versions.
The press release also states that the car gets Brabus' titanium sports exhaust system. This system increases the power output by 10bhp giving the SLS 573bhp to play with. The exhaust system is also 12kg lighter. I suppose both of these small improvements would only enable the Widestar SLS to power past a standard SLS by a mere whisker or so.