I tried finding any assistance and basically it looks like we're
right, it doesn't work. They give some ideas, of course one involving
the tank, then another with the destroy all cars cheat, which would
mean the game knowing you cheated, or the deadly vehicle cheat, same
again, the game knows you cheated. The last one is kind of like the
fast food one but I can't try it just yet. It says to take an FBI
rancher onto the julius highway in las venturas and start vigilante,
then just drive round on the road, so basically it says it works in
the same way as fast food. problem obviously is getting an fbi rancher
and getting onto Julius highway, by when you could have a tank and
complete the mission anyway.