If you are looking to set your Mini apart from others consider this undermount Wood & Pickett style flare set. This style arch mounts to the edge lip of your Mini rather than through the side, and uses a nice rubber moulding at the edge for a smooth look. Made from flexible black ABS plastic, can be painted or left raw. About 2.5" at the top of the flare, recommended for 10 and 12" wheels.
 
Supplied as a set of four arches and includes moulding.