Old abused engine care

[Tsuru]

Well, it was more aboot turbo cooling after engine shutdown than fanboyism...

For the others:
Issue especially on 2000' 1.8T for VAG, after shutdown the engine cooling just stop, with turbo still hot (since it was a small one to make up for displacement at lower rev it was kicking early and therefore always be on the warmer side even for supermarket runs). Sooo that meant that you had a engine bay working like a dutch oven. The timer is used to idle a bit a shutdown to allow for some cooling.
It's not a factory option because it ruins the mpg rating... And these days with idle stop it might be quite a mess to install...

Turbo's are made to run hot, they are part of the exhaust. I would think it's more about cutting off the all-important oil pressure when turning off the ignition causing excessive wear on the bearings when the turbo is still trying to dissipate its kinetic energy and spinning down from 13 gazillion RPM. Best let it idle for a bit before switching off if you pull in to a rest stop from highway speed. More cooling due to the coolant (and oil) still being pumped through it is a nice bonus.
Not that manufacturers generally give two shits about things that might happen when the car is out of warranty, which is of course how you get stop-start systems on turboboosted engines.

[Coligny]

Yes, that's what turbo timer do. Keep the engine running at idle after shutdown to allow all the cooling to work while there is no load and at low rpm/turbo rotation or boost.

Avoiding the dutch oven effect in the engine bay...

Having the habit of... Brilliantly engineered French cars... I always pop the hood at wee stop on highway rest area...
The Note was always super warm... The Delica is a fucking mystery, the hood is alway cold no matter the season after a ride. Then once every 4-5 month he heat like a bitch smell melted plastic and let the fan run for 5 minutes after shutdown, I suspect it's the automatic particle cooking from the catalyser thingy that oblige this behaviour. The Xtrails have a manual switch for this... Delica, not even a warning light... (How long to wait before the locals discover adblue... Can't wait to tell I have to buy some piss to run the car...)