Products have one to many relationships

-- HikaShop version -- : 2.3.5
-- Joomla version -- : 3.3.1
-- PHP version -- : 5.5.15
-- Browser(s) name and version -- : chrome

Hello Team HikaShop!

My site sells auto parts. Parts all have a year, make and model, but a part can be used for more than one year, make or model of vehicle. How can I structure this with Hikashop?
I bought HS Business edition thinking that I could create custom fields for this purpose. I created a custom field Year for products and started entering years, but when I go to a product, I can only assign one year. Problem is, a part can be used for several different Years.
Any ideas?
Many thanks in advance....