What you need is not the decoupling of the model & year, instead you need the option to enter multiple sets of make/model/year for the same product. As it is you can only enter one set, so when a remote is available for different years for different models, the search fails. i.e. you have a remote for VW Jetta, 1999 and Audi TT, 2000. When there is a search for 2000 Jetta, this product shows up. What you need is a way to enter these two as two different sets. You would add VW Jetta 1999 first, and then Audi TT 2000, separate from one another.
Regards