Note: This trick requires the v1.1 patch. To salvage mechs almost totally intact, enable the "Invincibility" and "Jump Jets" codes. Then, jump up and land on top of them until they die in a "death from above" maneuver.
Stealth kills
If an enemy mech is on the other side of a wall, ram into the wall and zoom in. You will be able to see and shoot through the wall. Note: This trick works with mountains and other walls that can not be destroyed.