Cart
From Halopedia, the Halo wiki
The cart is a vehicle that can be driven in Halo Reach. It can be found during the second level, early on. It is located head straight past the first right turn, by the forklift.
This vehicle can be useful as a mobile sniping platform against the Elites nearby, but after that, it cannot be taken to the next area.
Description
The Cart looks like a luggage transport at an airport, having a yellow color and being attached to some other non-drivable carts.
It is mainly flat, with a small "fence" on top. A second player could use it as a mobile sniping platform.