If you want to get off the map of Burial Mounds, then all you need is:
1. Two people (at least) with overshields, and a wraith.
2. First, you get in the wraith and have someone hop on the back without meleeing you.
3. Then, on the far side of the level that has a hill that you can see the sun on, back the tank up until it wont move any more.
4. The person on back hops off.
5. The person in the tank turns the tank to face the person on the hill (needs full oversheild), go as close to him as possible, and use the wraith's boost.
The person should be launched onto the other side. it might take a couple of tries but it will work.