Well at least he's not called Hoist and a decepticon.
Granted he isn't a military based vehicle I know but it could have been a lot worse.
He does somewhat resemble his orig alt mode, minus the cannons, and at least he is the right size, big and beefy.
.
There must be other reasons ($) they used a tow truck though and not any of these, maybe the sight of a rocket laching truck trundling down the street might cause a bit of panic. Also I don't think you can rent them for a movie to easily.
Any of these would have been fine, but too late now.
Semser (Israel / Kazakhstan)
Bereg (Russia)
Archer (Sweden)
or if you want the new style onslaught
HEMTT
Altough the American one is a bit small
M142 HIMARS
We now return to your regulary scheduled MB hating