Custom multi-step web application engineered for dynamic tax and import cost calculations on comoimportarmicoche.es (Motorzelo).

Built to eliminate manual estimation errors, this custom tool evaluates vehicle parameters (country of origin, official CO2 emissions, first registration date, and purchase price) to automatically compute regional transfer taxes (ITP) and total import expenses across different Spanish autonomous communities in real time.

Key Engineering Highlights: • Custom Calculation Logic: Developed lightweight PHP & JavaScript algorithms based on official government valuation data and regional tax brackets. • Stateful Multi-Step UI: Built an intuitive 5-step form flow featuring real-time state updates and an instant cost breakdown side panel. • Native WordPress Architecture: Integrated seamlessly into a custom WordPress setup with zero reliance on heavy third-party plugins or bloated page builders. • Performance & UX Focus: Engineered for instant client-side calculations, clean DOM structure, and responsive execution across mobile and desktop.