These are the Cadian's Recce sleds. They are HALO 'warthog' toys with Cadians in them. The guys in the seats have sentinal pilot bodies cut off just below the knee. The sheilds on the MWIK bit are original; the HALO rotary cannon was hacked off and spare sentinal autocannons added.
There are three of them at the minute. I suspect that competitvely priced (in points) they might be quite good; mobile (fast) heavy weapon installations. Like a Vyper. But different.