[kartelan02]

I also want to know what the best product is for protecting the interior from future stains/dirtiness.

Have you tried universal protectors for plastic, leather, vinyl? They are very effective for car interior dressing such as Fortador LeatherVinylTrim , The Chemical Guys SPI220 , 303 Automotive Protectant in the article https://www.fortador-usa.com/blog/best-car-interior-dressing-interior-dressing-for- auto-detailing describes the pros and cons of these tools, as well as how to use them in practice. Recommend.