Tesla teaser video sparks speculation of long-awaited Roadster or mass market model

1. Tesla teases new car model amidst speculation of Roadster or mass-market vehicle. 2. Musk's history of unmet promises raises skepticism about timelines. 3. New mass-market model is critical for reviving sales amid European slump. 4. Tesla faces increasing competition from low-cost Chinese EV manufacturers. 5. Recent delivery increases were artificially inflated due to tax credit expirations.