Specifically the A-rack transport (http://starwars.wikia.com/wiki/A-rack)
I like this idea, the Hand could do with more units to fill out their ground unit roster and it makes a change from generic [insert name] tank. I think Zahn is running out ideas though, "A-rack" is pretty unimaginative!
Also, a bit more detail of the unit from page 444 in my copy of Heir to the Empire 20th Anniversary Edition:
The A-rack was a simple device, one that Lhagva was told had been adopted from one of Thrawn's other liberated worlds. It looked very much like an A-frame, fold-up clothing roller of the type he'd seen been pushed or pulled along busy walkways back in his own home city's garment district. The A-rack, though, was much sturdier than those, with oversized wheels, a top-mounted E-Web/M heavy repeating blaster, a center-mounted engine, and enough room on each side for five stormtroopers to stand facing outward. With the pair of cramped seats in the center section for the driver and gunner, the carrier could transport a full stormtrooper squad quickly and efficiently across medium-rough terrain.