This might be of interest, a complete list of external camera positions for different vehicle classes.
All
extCameraPosition[] = {0,2,-20};
Car
extCameraPosition[] = {0,1,-10};
MotorCycle
extCameraPosition[] = {0,1,-10};
MotorCycle/M1030
extCameraPosition[] = {0,0,-3};
MotorCycle/TT650
extCameraPosition[] = {0,0,-3};
Tank
extCameraPosition[] = {0,1.5,-9};
Man
extCameraPosition[] = {0,1,-3.5};
Plane
extCameraPosition[] = {0,1.4,-25};
Plane/Camel
extCameraPosition[] = {0,1.2,-13};
Helicopter/AH6
extCameraPosition[] = {0,2,-15};
Boat/RHIB
extCameraPosition[] = {0,4,-14};
Boat/Zodiac
extCameraPosition[] = {0,1.5,-4};
Boat/PBX
extCameraPosition[] = {0,4,-14};
I believe the format is X,Z,Y as opposed to X,Y,Z
Planck