My 2017 GTI Sport is leaking coolant at 33k miles. From my searches this appears common. Dealer said they need to replace the thermostat housing unit and they'd cover it under warranty. I left it overnight, now they call today asking to charge "up to $620 for 4 hours of extra labor" because my aftermarket intercooler (the Magic intercooler from Ebay) and "aftermarket pipes" will require them to remove the entire front bumper to replace the thermostat housing unit. They said they'd still cover the repair under warranty but that my aftermarket parts (I have intercooler, turbo inlet and downpipe) require more labor to replace the part. Does this sound even remotely right or should I take it to a different dealer? This was University Volkswagen in Seattle.