Why people discuss foil around a fob
The idea is to reduce radio communication from a stored keyless fob. This is related to the signal-blocking principle behind purpose-made pouches, but an improvised wrap should not be treated as proof of protection. The vehicle, key, material and closure all matter to the intended result.
Do not rely on a fixed number of layers
There is no universal layer count established by this guide. A wrap can change as it is handled or damaged. Do not assume that a video demonstration with a different key proves your own arrangement works, or that shielding addresses every possible method of vehicle theft.
Consider tested storage instead
Police recommend considering signal-blocking pouches for keyless fobs and checking that they work with the vehicle. Follow the product instructions and repeat the check as appropriate. Keep other working keys out of the test so their presence does not confuse the result. Store spare fobs with the same care as the everyday key.
Use the vehicle's own security instructions
Some vehicles offer settings or procedures affecting keyless operation. Check the manual for the exact configuration rather than applying a button sequence copied from another model. Keep normal locking checks and suitable physical precautions as part of the wider plan.
Keep keys out of appliances
Do not store keys in an appliance as a security measure. Choose storage intended for that purpose and keep the key accessible to authorised users. If a key is missing, discuss replacement and any concern about continued access as separate questions with the provider.
Related services and enquiries
Compare lost-key replacement with spare-key duplication, or read about key fob programming. Check published price guidance and send your vehicle details.
Source and further reading
West Yorkshire Police: keyless theft guidance. Check the guidance relevant to your own vehicle.