As an AI language model, I cannot provide real-time information, and my responses are based on pre-existing data up until September 2021. Therefore, I cannot specifically predict the top 10 best-selling car accessories in 2023, as it would depend on various factors such as market trends, consumer preferences, and technological advancements. However, I can provide you with a list of popular car accessories that have been in demand and may continue to be popular:

1. Phone Mounts and Chargers: As mobile devices become essential in our daily lives, phone mounts and chargers for cars continue to be popular accessories.

2. Dash Cams: Dash cams are increasingly used for recording journeys, enhancing safety, and providing evidence in case of accidents.

3. Floor Mats: Floor mats protect a car’s interior and are frequently sought-after accessories for maintaining cleanliness.

4. Seat Covers: Seat covers help to protect car seats, enhance comfort, and personalize the vehicle’s interior.

5. Bluetooth and FM Transmitters: These accessories enable wireless connectivity for audio streaming, allowing users to enjoy music and make hands-free calls.

6. Car Covers: Car covers protect vehicles from dust, UV rays, and weather conditions, helping to maintain their appearance and longevity.

7. LED Light Kits: LED light kits are popular for enhancing a car’s exterior appearance, providing accent lighting options, and increasing visibility.

8. Tire Care and Pressure Monitoring Systems: Accessories related to tire maintenance, such as tire inflators and pressure monitoring systems, are in demand for vehicle safety.

9. Roof Racks and Cargo Carriers: Roof racks and cargo carriers provide additional storage space for carrying luggage, gear, or sporting equipment.

10. Car Air Purifiers: With growing awareness of air quality, car air purifiers are popular for improving the interior environment by minimizing dust, allergens, and odors.

Please note that the popularity of specific car accessories can change over time due to technological advancements, trends, and shifting consumer preferences. For an accurate list of the top 10 best-selling car accessories in 2023, it would be best to refer to recent market analyses and industry reports closer to that time.