[Marricio]

pawn Код:

public OnPlayerEnterVehicle(playerid,vehicleid)
{
if(vehicleid == 123) // Switch 123 to your vehicle ID
{
if(gTeam[playerid] == TEAM_COP) // or GetPlayerTeam
{
return SendClientMessage(playerid,COLOR,"You are cop. You must defend this vehicle from stealers!");
}
else
{
return 1;
}
}

Not tested, might work? :l
Ps:Sorry for identation