C-6 Interior Care

I just purchased a new C-6. The interior materials are a different finish than my C-4. Reading the C-6 owners manual under car care it basically recommends not using any protective cleaners/conditioners on the dash/doors or leather - basically mild soap and water throughout interior. I intend to keep this car a long time and this Chevy advice makes no sense. Has anyone found products that are compatible with the C-6 flat matte interior finish and leather seats. I am concerned that I don't change the interior finish or the cashmire leather color.

I use just the mild soap and water to clean and then protect it with Aerospace 303 UV product that offers maximum UV protection and a flat finish.

Thank you for the information - can you tell me where I can buy the Aerospace 303 product