303 (30313-CSR) UV Protectant... https://www.amazon.com/dp/B00KN0UOEE?ref=ppx_pop_mob_ap_share
A matching spare is a beautiful thing, just spray some of that on the tire, all your tires for that matter.
Interior: Anything from 303
https://www.amazon.com/303-30313-CSR-Protectant-Plastic-Fiberglass/dp/B00KN0UOEE
(they make leather care products too)
And try to make sure no one is getting in the car with brand new blue jeans. Pretty much anything else will come out.
There are lots of good detailing channels that will describe proper washing, too, but 2 buckets, foam cannon, etc. is all best practice, and I keep a detail spray with CLEAN microfibers in the car at all times for bird crap, etc.
Consider ceramic coating for the exterior, too; worth its weight in gold.