When at a certain range from groundvehicles they will display as a little black dot standing out VERY prominently in the terrain. This makes it easy for enemy planes to find them...even if they are hidden inside buildings or heavy tree-cover.
HT has made extensive effort to reduce the visibility of vehicles, why this hasnt been fixed yet, is way beyond me... and VERY irritating, when sneaking around for half an hour, only to have an enemy barreling in from 10k distance on a beeline to take me out.
Litjan