It looks like one of those rally vehicles and two NEST Hummers. Those Hummers never made it to production but they are they combat version that look like the Warthog from Halo. They had them in Dark Of The Moon as well.
The twins died off screen. They were going to be in movie 3 but I believe Bay wasn't happy with them in it and opted to have them out. There were scenes filmed with new versions of the their car modes but they were cut out of the final film.