The Sandwich is a rare strategy that rarely occurs in Multiplayer, and VERY rarely in single player. It happens by first targeting a target car, have another car go in the opposite direction you are going in into the target car, and hit the target car at the same time. If all goes well, the target should be crushed and sent flying, and you and your other "piece of bread" should take no or little damage.
You may want to use Radical One or M A S H E E N for this strategy. The main purpose of this strategy is alliance work and revenge. You will need to then surround the target car and hit it either from front and back, or left and right. A four way alliance can do the Four Way Terror, and it WILL mean certain death for the target if he/she gets surrounded. The Four Way Terror is doing the Sandwich front and back AND ALSO left and right so the enemy is boxed in.
To do this attack, follow these steps:
1. Find a target car, usually small cars for starters.
2. Tell your alliances your target car that you have selected.
3. Take 1 alliance member (or 3 if you want to the Four Way Terror), and line them up.
4. Pick a direction in which you want to attack from (preferably front and back, or the Four Way Terror)
6. If all goes well, they should be wasted and steer clear of your alliance member.
6A. If not, go back to step 2 or try a different strategy.
This has a 45-50% chance of working well.