1-Put a barcode on the box ( possibly extend to the second plastic seal)
2-Upon purchase return the box to Patek headquarter in Geneva (AD is responsible for it)
3- Upon receipt Patek enable the warranty, only done if come with an AD ID tag/ declaration, with date of purchase.
Rolex now enable warranty with credit card terminal (bought a Rolex recently and was done so).
So if serious to act against plastic, there are modern ways to do it.
Cheers,
Phileas.