Here's the absolute DIRT supereasy way:
1. Get the Hind
The precise way to do this is:
Grab one guy, get in the MG Jeep and drive S from the base -- road will turn W. At the T turn N. The road will bend W into a base. Kill the two guards on the perimeter. Drive into the base, and get in the fuel truck. Drive the fuel truck out the W gate, and you will spy a Hind. Pull up, get in hind, refuel.
2. Kill the Scud
Now, you know where the SCUD is, so fly the Hind fast E over the scattered enemy until you're due S of the point on the peninsula where the hind is. Save game here. Turn N and choke off missiles at the targets that appear. You should get the "Scud killed" message.
3. Kill Guba
One little-known fact is that Guba never makes it to the port. His UAZ breaks down. So the best way to catch Guba is to fly back to where you took off from, then head up to the road and patrol until you find a UAZ. Land and take down the SpetzNatz dudes. game over.