Adding product to cart via API?

We need to make a product selector, then using the selector to get the product code and add those to cart, also modifying the product description at the same time…

For example - Customer selected say product - mirror for car model A, but same mirror is used in Car model B and Car model C.

We want to add the product to cart - with description “Mirror for car model A” via API (or other easier ways?)

(If they select mirror for Car model B, we would like to add the same product to cart, but with Description “Mirror for car model B”)

Any thoughts guys? any help would be great!