I need a straightforward way for visitors to pick their exact vehicle before browsing parts—just like the big auto-parts sites do. On my existing OpenCart store, the filter must let shoppers narrow results by Brand, Model, Year, Engine and, where available, Body style. Once a customer locks in those selections, only products mapped to that specific combination should appear. What I’m after is either: • a ready-made OpenCart extension that already handles these attributes, or • custom code that installs just as cleanly through the admin panel and follows OpenCart standards for updates and security. Key points for the build • Filter steps: Brand → Model → Year → Engine (and Body when present). • Data needs to be managed in the back-office, so I can import or edit fitment tables in bulk. • Must not slow down page load; Ajax or other lightweight loading is preferred. • Works with the default theme (I’m on the latest 3.x) and stays compatible with child themes. • Clear install guide plus a short note on how to assign new products to vehicle combinations. Deliverables 1. Extension/module package in .ocmod or vQmod format. 2. SQL or CSV sample showing the fitment table structure. 3. Step-by-step install and usage documentation. If you already have a solution that ticks these boxes, great—show me a demo link. If you’ll build it from scratch, outline the timeline and any milestones so we can move ahead quickly.