The SL-C has an opening in the roof to duct air. But unless you add a duct like this one, the air, and anything else ingested at the roof opening (like water) will make its way into your interior, usually at the worst time.

This fiberglass duct is custom made to seal the roof opening, and duct air cleanly to the engine compartment for cooling (or for engine air intake, with more engineering). Most people just use it to seal the interior from hot air and water.

Fits great, and is intended to be bonded to the underside of the spider (i.e., the roof) of the car while under construction. Made of fiberglass, and used in many SL-Cs.

Contact Jack Moeller at ??? for availability and shipping info.