All the signs will come down, and many of the bathroom signs have already been removed.
The Georgia-Pacific paper goods division of Koch Industries signed a 10 year sponsorship agreement with Disney theme parks in January, 2005. Brawny at LMA! and Big Thunder Ranch Petting Zoo, Dixie Cups at the Hungry Bear Restaurant, Sparkle Paper Towels at Gadget's Go Coaster, etc.
Koch Industries has allowed their Georgia-Pacific sponsorship to expire without renewal, and the signs are coming down at the 10 year mark from when they went up in the winter/spring months of 2005. By May they'll all be gone.
As for
National Car Rental, they are still an active sponsor. And it's National's parent company,
Enterprise Holdings, that still has an active sponsorship with Disney's parks.
Alamo Rent-A-Car is another car rental division of Enterprise Holdings, and Alamo is still the sponsor of
Luigi's Flying Tires even during its year long transformation into a totally different ride. The Alamo logo is even plastered on the refurbishment signs on the Luigi's construction wall, per the Enterprise Holdings sponsorship agreement.