Multiple match fields in order system?

[wireshop]

Ok I have a table "inventory" which contains information like price, part number, and two fields "year" and "make". Most of the parts work for multiple years and even multiple makes. What I want to do is to create an "Orders" layout that automagically shows all the parts we sell for the year and make of the car/truck that the user enters(there will probably be no more than 20 parts in this list). The user can then add a quantity to each line item to add it to the order.

I have thought about using the "year" and "make" fields as multiple match fields but that would require selecting each year and make from a popup menu in the inventory table???

Another thing to keep in mind is that the Inventory table will be exported as XML for use in the website.

Any ideas on implementing this order system?

[wireshop]

Not getting any responses from this so maybe I'll clarify. What I want to do is to have two fields "year" and "make" in the orders table these fields match to the "year" and "make" fields in the inventory table. I was thinking about using the "year" and "make" fields as multiple match fields. i.e. there is more than one value in the field each seperated by a carriage return. My question is what is a simple way to have the user input the data into the inventory table. Or am I looking at this completely wrong