Hints:

Invincible Demolition Trucks
     Build five or six Demolition Trucks and have a fully charged Iron
Curtain  ready.  Drive  the  Demolition  Trucks into an enemy base and
engage the Iron Curtain on them before enemy weapons can hit them. The
Demolition Trucks will not explode until they reach the target.

Trojan Bus
     When  playing as the Soviets, use a Yuri to mind control a school
bus.  Load  five  infantry  units  into the bus and drive it inside an
enemy base. The Allies will not fire on the bus.