It is not uncommon for Roadster owners to discover the following piece of plastic trim lying within the driver's footwell:

At first, it is not immediately obvious where this comes from. The trim is part of the interior ventilation system and ducts air to the driver's feet. We have found a couple of Roadsters which did not have this duct at all. Fortunately, thay are available from smart and only cost around £2.  The duct has the following part number:

Q001 4594 V001 0000 00 (right hand drive)

Its installed location is shown here: