Complex sentence: The 1921 Heine-Velox was advertised as a custom-built luxury car, first shown at a San Francisco auto show had hydraulic brakes on all wheels, and V-12 engines commissioned from "Weidely".
Split into simpler sentences: The 1921 Heine-Velox, advertised as a custom-built luxury car, it was first shown at a San Francisco auto show. The car had hydraulic brakes on all wheels, and a V-12 engine commissioned from "Weidely".