Elon Musk ratchets up attacks on Navarro as Tesla shares slump for fourth day
1. Tesla shares dropped 22% in four days amid trade tensions. 2. Musk criticized Navarro on trade policies negatively affecting Tesla. 3. Tariffs threaten Tesla's production costs due to imports. 4. First-quarter deliveries fell 13%, missing analyst estimates. 5. Musk calls for zero tariffs between Europe and North America.