The "D" mode, stationary effect is very different to a conventional auto, in that an actual gear ratio (1st) is actually engaged, and the corresponding clutch pack is held just off the bite point.
Yes but isn't that "rubbing" (however lightly) a bad thing? Is it good practice to put it in N when waiting at lights? It would be a lot easier if you could shift it in and out of "N" with the paddles
Not really. The box and clutch packs are working as they were designed. The clutch packs are actually immersed in oil, just like most motorcycles (except Ducati), and the oil carries away any heat build-up.
If you know the lights are going to be a long while on red, then of course it would make sense to apply the handbrake and put it in "N". You'll stop dazzling anyone behind with your brake lights too!
The paddle shift into neutral is not a good idea, because you need the interlock (foot on the brake) to stop you going into reverse accidently.
People really shouldn't call the DSG an "auto" - OK, it does have an automatic "mode", but the difference in it's design and construction between it and conventional auto is like - say, trying to say hockey and rugby are the same, afterall, they are both played with a ball!! I suppose something like an "automated, electronically controlled, dual unit manual gearbox, twin multi-plate oil-bathed clutch, with sport mode and sequential manual shift mode" is actually a bit of a mouthful!!! As we were!
Rgds