Wordpress - post_meta vs taxonomy vs custom table

Question

I'm building a car services database. Each car service is able to repair multiple models of cars.

What is the best way to store the relation between car services and types, to be able to later query that?

My options are:

• for each car save the models as post_meta as separate records (not an array) and use the Meta Query.
• create the list of models as a custom taxonomy and use Tax Query
• save id of the post and car model into custom relational table and modify the where and join clauses of WP Query

I'll have cca 3000 car services, each service might have cca 20 models selected.

What's the preffered way? Any help appreciated.

Answer 1

Depends on what additional information do you need for car models.

If you'll be using this only as a filter (or searching) use custom hierarchical taxonomy with top terms being car makers and models as be their children.