Try running this script in the init field of each vehicle you want to proctect.
// Only pilots.sqf
// Only pilots piloting
_vehicle = _this select 0;
_pilotstypes = ["SoldierWPilot", "BISCamelPilot", "SoldierEPilot", "BISCamelPilot2"];
_driver = objNull;
while {damage _vehicle < 0.5} do
{
_driver = driver _vehicle;
if (!isNull _driver) then
{
if (!((typeOf _driver) in _pilotstypes)) then
{
_driver action ["GETOUT", _vehicle];
};
};
Sleep 1;
};