Yup, changed mine at 120 000km, it's an 02' RS.
My mech said he's done tons of those, he diagnosed it with me on the phone lol.
He also said replacement seal where thicker or different somehow which leads me to believe they could have nipped this in the ass earlier.
Volks GTI's blow heator cores and ignition coils, I guess every brand has an achilles heel, except with the VW it's bumber to bumper
Brys how often should the coolant be changed to avoid this?