Keyword internal search

This is a bad idea – when you accept input, you need to control and validate that input as much as possible. Otherwise, it won’t take long for your data to be a mess of keywords that are mis-spelt, wrong, etc, etc, etc. It sounds as tho you are using Roles and Permissions to allow vendors to submit data based on their products.
Yes?

A better approach is to have far more control over the input, and use that same input as the output.
Something like:
– create a frontend web form for vendors to input their products
– the webform provides the input validation for the vendor to select (make, model, year, colour) from pre-built lists
– the webform populates your tables for the front end user to facet his search results like this:
https://facetwp.com/demo/cars/

This is scaleable long term, far more accurate, and little maintaince from you.

Thank You very much for the reply!

My site is for car parts not really cars, which is making it more difficult to filter the results. I had a website with filters and it did not work, people just weren’t using them properly because vendors are not willing to use them, because it was too slow for uploading process. One of my vendors has 12 000 car parts that can match on 3 to 6 cars from different years. For example Renault Laguna III has parts matching from 2007 to 2015 on jist that car, nit to mentione the other cars from renault group in that time frame.

There are over 200 car parts on just one car, those car parts can fit on multiple vehicles (volkswagen parts can range from 3 to 6 vehicles that match the part), so for my vendor and for me would be a lot easier if they can type tags (keywords) that are relevant for their ad. For example: left door, golf, 5, 2006 – those 4 keywords would match when searching for such things. Also if the car part is matching multiple cars, a simple keyword added can fix the search and make it easier for my vendors. Thst is why it is easier and faster to type in keywords than to use filters (car part vendors are not the easiest people to work with, so we have to negotiate a more simple way)

One of the reason thr filters do not work is because the main competitor is olx (seling everything) and their website is messy, but all the visitors are behaving the same and it is hard to change it, so I have to incline towards them. I am only in cart parts industry, but the olx was there before and kind of set the bar for the visitors behaviour, unfortunatelly. They have filters, but not in car parts section, only a category for car parts, so whoever comes to my site is trying the same way of searching.

Understood.
I would implement a stronger search tool that includes stemming and fuzzy:
https://en-ca.www.ads-software.com/plugins/elasticpress/
https://en-ca.www.ads-software.com/plugins/solr-power/