Have you heard about the infinite grenade and missile glitch, with the Banshee?
Very secret, I only share if you don't tell.
Okay, so.
First, you have to have a PS3 and a team of 4 Demolisher Engineers.
Pick Rio/Collectors/Platinum. As soon as wave 6 begins in the middle, all four of you need to run to do box on the other side of the map,wait and count to 5, then run to the LZ, like crazy. (I reccomend Adrenaline Mod III).
Here comes the tricky part though. You have to fight off all the Primes and Praetorians, until all the Banshees get there. As soon as at least one Banshee arrives, you have to put down your Supply Pylon at the same time, right at the feet of the Banshee. But only if she's glowing, otherwise it's not gonna work.
We usually use a mic, and count to 3, and 1-2-3 we put down our Pylons, and all of us will have unlimited Arc and Homing Grenades, and the Banshee will become friendly and will fight alongside of you. It will sync-kill Primes and Praetorians.
It's hard to pull off, but it's so much fun!