Remove the small carpets. Shake them to remove the worst of the dirt, rocks and larger items that might be on the top surface.
Vacuum all the car's carpeting, including the small foot rugs. Use an appropriate vacuum attachment to reach into the small spaces.
Add attachments to the steam cleaner to reach small spaces of the car. Activate the steam cleaner. According to directions, add cleaner to the steamer or apply it to the carpet.
Run the steam cleaner attachment over the carpets once it has steam. Clean the small rugs in the same manner depending on the steam cleaner.
Allow the car carpets to dry completely with the doors open. Replace the small rugs after the rugs and interior car carpets are dry.