The insulated Coolant Recovery Tank:
Also visible:
- reflective-insulative material on bulkhead;
- insulative material on inner fender beneath Coolant Recovery Tank.
(Strut tower has also been insulated after the picture was taken. Also coolant hoses and gasoline hoses which appear unwrapped in the photo.)
Note: it only works on an engine where coolant pump draws directly from the coolant tank when engine starts. VAG 1.8T, 1.9TDI, 2.0TFSI engines are made such. Older, 1960s to 1980s engine designs where coolant overflow tank took the overflow from the radiator can't do this.