"Presumably you do that before you get the shopping out of the car."
And I imagine most people have their door key on the same keyring as the car key so why not just use that (so none of "it's something we all do when we get home: rummage around in your pockets or bag, find your keys, identify the one you want and then stick it in your front door to gain access")?
In agreement too because this feels too much like a solution looking for a problem.