I've had 2 different developers say they can do this, but cannot seem to make this work.
Fitment Table: Year, Make, Model, Application, Fitment ID
Magento Product: Fitment ID is a field on the Magento Product level that will list the Fitment IDs it will fit. This can be any value, and any number of values, defined completely separately from the Fitment ID in the Fitment Table.
The relationship between the Fitment Table and the Magento Product is not a 1:1 relationship.
When selecting a Year, Make, Model, the Fitment ID will be the search criteria to pull ALL Magento Products that match this Fitment ID.
That is definitely possible but its implementation is the most important aspect (as always!).
You should ensure that the performance is good when you customize Magento at that level.
I've seen that customization in projects that implement a custom search by width/height/etc.