As an AI language model, I can provide you with some tips on how to use a Sat Nav legally and safely:

Set up your Sat Nav before driving: It is important to set up your Sat Nav before you start driving to avoid being distracted while on the road.

Choose a safe and secure location for the Sat Nav: Make sure your Sat Nav is securely mounted to your dashboard or windscreen in a place that does not obstruct your view of the road or any important safety features such as airbags.

Use voice prompts: Most Sat Navs come with a voice prompt feature, which means you can listen to directions without having to take your eyes off the road.

Plan your route ahead of time: It is important to plan your route ahead of time so that you are aware of any potential hazards or traffic delays.

Keep your Sat Nav up-to-date: It is important to keep your Sat Nav up-to-date by regularly updating the software and maps. This will ensure that you are receiving accurate and relevant information.

Use common sense: While a Sat Nav can be helpful, it is important to remember to use common sense and be aware of your surroundings. Always follow road signs and obey traffic laws.

Pull over if you need to adjust your Sat Nav: If you need to adjust your Sat Nav or enter a new destination, it is important to pull over in a safe and legal location before making any changes.

Do not rely solely on your Sat Nav: A Sat Nav should be used as a tool to assist you in your journey, but it should not be relied upon as the only source of information. Always use your best judgement and be aware of your surroundings while driving.