Anyone know how these work? Just bought a Peugeot 806 with one fitted as standard. It seems that some direct injection diesel engines are so efficient that they can't maintain a sufficiently high coolant temperature in cold weather. The supplementary heater seemingly automatically turns on at some point and heats up the coolant. Haven't witnessed this yet as the weather hasn't been cold enough. The Webasto website claims it can be upgraded to parking heater which can be controlled remotely. The Peugeot manual tells nothing other than that the car might have one fitted. The local agents know nothing and Webasto themselves don't respond to e-mail.
Would be interested if anyone had tried the upgrade, how much it cost and whether it was worthwhile.