Engine Knock: Causes and Solutions

hello,
in the thread /viewtopic.php?t=1849&highlight=lupo, it is stated that the solution is to replace the engine mount.
That's the workaround.
Is this being offered as a courtesy, or does the customer have to pay for it?

'For some time now, my Lupo 3L has been making a rattling noise on the front right side when I drive over bumps.'
Initially, it only occurred when driving slowly in neutral over small, successive ground waves.
It sounds like the strut mount, when it's broken.
That's not the case, though, because I rebuilt it with a new chassis.
Meanwhile, it's also making a rattling noise, but again, only with small vibrations.
It's definitely the engine mount on the right side.
Does anyone know if this has happened before with a Lupo 3L?
greetings