@sumogtr; if your car is new, then you should be able to temporarily disable the keyless entry function too - this works for some current model VW’s and Seat’s (I think it works for the current model Leon with keyless entry).
To temporarily disable keyless, lock the car using the lock button on the key fob, then within 5 seconds, touch the sensor on the door handle that you would normally use to lock/unlock the car. Car will then not unlock by just touching the handle (so should be safe from would-be thieves with signal amplification relay equipment) - the ‘unlock’ button on the key fob needs to be used to unlock the car.
This procedure has to be done each time you lock the car. No hardship really, as you’d use the key fob buttons if you didn’t have keyless anyway.
Back to your original question. These are expensive but recommended recently by a member on VWROC.com forum;
https://www.amazon.co.uk/Alpha-Shield-Premium-Keyless-Aluminium-Schwarz/dp/B077JCQFXQ
They do look to be excellent quality, but are just large enough to take a single car key, so key rings / other keys would need to be removed. They should last a lifetime though, and there should be no risk of them failing like there could be with a Faraday pouch if the protective lining becomes damaged or worn over time.
It would be necessary to buy two though, unless you keep the spare key in a Faraday pouch (or similar).