When fitting much bigger wheels to the roadster like the 18" Brabus alloys steering restrictors are required to stop the wheels fouling the inner arches on full lock.

The steering restrictors were supplied upon purchase with the Brabus 18" wheels, there is no associated part number, but a similar restrictor should be able to be fashioned based on the steering arm size underneath the gaitor.

Open the front boot of the car and remove the bonnet bin.

Looking at the steering rack you will see a plastic cover.

Remove the plastic cover by pulling out the single retaining clips either side.

Remove metal clips holding the gators on the rack circled in yellow below.

Pull back the gaitor so you can access the inside:

Insert the restrictor and make sure its secure:

Repeat for the other side:

Pull back both gaitors and secure them with 55mm jubilee clips and replace the plastic trim removed earlier.

Depending on the size and offset of the wheels fitted these should be more than enough to restrict the steering, if more is required then there is room for another set to be added along side.