Finding: /p5fiat/extern/vehicle/models IS the endpoint (de-licensed, demo:false) but
returns 'Cannot parse null string' regardless of manufacturer/make/brand param — needs
an undiscoverable param from the P5 SPA session (launchCatalog.do flow). Requires a real
PL24 web-UI network capture to resolve. Turkish Tofaş NM4/Egea is not in this catalog
anyway, so catalog-browse value is European-Fiat-only. Kept the generic P5 endpoint
self-discovery fallback. Fiat VIN-decode (European) is unaffected and still works.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>