tick over OT

They are saying that VAG TDI (and probably any modern diesel) won't warm up well at idle, as the design is relatively thermally efficient. IME that's pretty true. It will warm up at idle eventually, but it will take a long time.

I thought the idea was to get the engine warm asap because then it's at the correct 'operating temperature'. Or does the VAG TDI not allow heat from the engine into the passenger compartment until it has reached its correct temp?

The idea *is* to get it to temp quickly, which is why you shouldn't leave it idling, but start it and then drive. The heater will work straight away- it's just the engine will take forever to warm at idle.

If you have climate control, it won't run the blower fans (except on defrost setting) until the coolant warms a bit.

Next time I'm in the same situaion I will turn the engine off.

The negatives seem to overweight the benefits.