The gearbox fluid should be changed regularly (owners manual calls out at least every 2 years). In my case, it wasn't clear when the last change had taken place so I decided to do it immediately.

I recently picked up a '06 Gransport. Everything is pretty mint on it except for the interior is starting to turn sticky. I looked at a lot of options, and what others were trying and decided to try something a bit different. The first piece I decided to try was the center windshield vent.  I received a quote from a commercial outfit that would refurbish this part for $350 USD. I started by trying to scrub it with goo-gone and although it got rid of some of the stickiness, it left a lot of scratches and some lighter splotches of discoloration. It looked better but wasn't great. 

Picked up in early October, 2019 is my 2006 GranSport in Grigio Touring Metallic, nick-named Macaroni.  Like all GranSports, it has the F1/Cambiocorsa hydraulically robotized manual gearbox.