Migbuster is correct...it's how I do it.
I have the target boxes but they are set so small they show as tiny red dots so that they're visible but don't detract from a more realistic view.
Same goes for waypoint indicators etc.
From my Huddata.ini....
[Display001]
DisplayType=DIRECTOR
ObjectType=TARGET_ENEMY
ConeSize=1
BoxSize=1
BoxType=SQUARE
BoxColor=1.0,0.0,0.0,0.75
ConeModelName=redcone
[Display002]
DisplayType=DIRECTOR
ObjectType=TARGET_FRIENDLY
ConeSize=1
BoxSize=1
BoxType=SQUARE
BoxColor=0.0,0.0,1.0,0.75
ConeModelName=bluecone
[Display003]
DisplayType=DIRECTOR
ObjectType=NEXT_WAYPOINT
ConeSize=1
BoxSize=1
BoxType=TRIANGLE
BoxColor=1.0,1.0,1.0,0.75
ConeModelName=whitecone
[Display004]
DisplayType=RADAR
PosX=0.865
PosY=0.015
Width=0.0
Height=0.0
Alpha=0.60
InitTime=2.0
[Display005]
DisplayType=DIRECTOR
ObjectType=RADAR_TARGET
ConeSize=1
BoxSize=6
BoxType=DIAMOND
BoxColor=1.0,1.0,0.0,0.75
ConeModelName=