Silicone waterproofing agents are typically designed for use on various surfaces to make them more resistant to water and moisture. They can be used on some car surfaces to provide water repellency and protection. However, it's essential to be cautious and selective in 

where you apply them, as some car surfaces may benefit from silicone-based products while others may not.

Here are some considerations for using silicone waterproofing agents on car surfaces:

Paint and Clear Coat: Silicone waterproofing agents can be applied to a car's exterior paint and clear coat to provide a protective barrier against water, preventing water spots and making it easier to clean. Be sure to follow the manufacturer's instructions and ensure the surface is clean and dry before application.

Glass: Silicone-based products can also be used on the car's glass surfaces, such as the windshield and windows. They can help repel rainwater, improving visibility during wet weather.

Rubber Seals: Silicone waterproofing agents can be used on rubber seals and gaskets, such as door seals and sunroof gaskets, to keep them flexible and prevent water from leaking into the car's interior.

Plastic and Trim: Some silicone products can enhance the appearance and protection of plastic trim and other plastic surfaces on the car. However, be cautious when applying them to avoid leaving a greasy or streaky residue.

Wheels and Tires: Silicone-based tire shine products are available to provide a glossy finish to your car's tires. These products can repel water and enhance the appearance of the tires.

Exhaust and Engine Components: Avoid using silicone products on engine components, exhaust systems, or any parts that get hot, as they may not withstand high temperatures and can create smoke or fumes when exposed to heat.

It's important to read and follow the instructions provided by the specific silicone waterproofing product you choose. Additionally, be cautious when applying any product to ensure that it doesn't create a slippery surface on areas like the steering wheel, pedals, or floor mats, as this could be hazardous.

Always test a small, inconspicuous area before applying any waterproofing agent to ensure it doesn't cause any unwanted side effects or damage to the car's surfaces. Additionally, consider the potential for the product to wear off over time, and reapply it as necessary to maintain its effectiveness.