1. Ergonomic Design: Designed to fit comfortably in your hand, even without a handle, for easy holding while driving.

2. Insulation: Typically features double-walled or vacuum-sealed insulation to keep drinks hot for extended periods or cold for hours.

3. Compact Size: Made to fit standard car cup holders for convenience during travel.

4. Leak-Proof Lid: Equipped with a spill-resistant lid to prevent accidents while on the move.

5. Durable Material: Often made from stainless steel or high-quality BPA-free plastic for long-lasting use.

6. Easy to Clean: Most handleless car thermos cups are designed for simple cleaning, with removable lids and wide openings for quick access.

7. Lightweight: Despite the insulation, these cups are often lightweight, making them easy to carry around.

8. Modern Aesthetic: Available in sleek, minimalist designs to suit various tastes.

These features make handleless thermos cups a practical and stylish choice for people who need to keep their drinks at the right temperature during commutes or road trips.