The steering wheel makes a slight squishy noise when cold. What could this be?

There is a service bulletin regarding this complaint/concern, but it pertains to vehicles used or exposed to areas where heavy road salt is used. Customers have noticed increased steering effort and noise from the steering column intermediate shaft for 2002-2005 Sedona. The increased effort is usually first noticed at low speeds with noise and or rattle. There is a updated part to address this concern. The cost to install this updated part if that is the source of the noise is about $267.72 . Hope this is of help. Vaughn @ Auto Japan

Excellent answer! To add to Vaughn's answer Kia as a car manufacturer put a lot of great technical information and work shop manuals on line for free for Kia owners. www.kiatechinfo.com