Hiding tanks

[Soldier]

You can turn the engine off (manual refers to it as idle) to cause the sound signature icon disappear altogether. I've been using that button religiously, but lately I don't feel it's necessary to do so.
Noticed that enemy tanks moving (showing sound icon) when come to a stop, for what ever reason, the sound icon automatically disappears.

There's only one really good way to hide your tanks, even in open terrain.
Played the scenario "Storm555" numerous times on both sides, and especially on the German side (defender) destroyed many a Russian T34 without being seen. Sometimes as long as three minutes, my panzers would fire on Russian armor, that never seen where all of those shots came from.
That scenario had two weather conditions, rain and fog, which I believe cut visibility down to 195 meters or so..
I positioned my Panzers at the outer limit of this maximum visibility 190 meters or so, back from a railroad embankment, which the enemy armor had to cross.
The rest is history.. Tank after tank went up in smoke. Later on my opponent revealed that he never saw the panzers.. :-)