Setting Up Music Truck for Carnival

I have a question, if you all can help :)
I've been searching all over and asking advice but no one has helped :(

Here in Trinidad, we do a lot of music trucks. My question is, what are some things i should be aware of when setting up a system as such. 

Let's say a Stack of 4 bass cabs and 4 mid tops on the rear, and 2 stacks of 4 bass cabs and 4 mid tops on each sides ans well as 4 mid tops on the front.

Would one need to delay the bass cabs  or channge polarity so that the bass is "heavy" and nice/ evenly sounding all around the truck? In addition does this apply to the mid tops as well.

The reason I asked is during this Carnival season i heard a lot of music trucks and there was hardly any bass - Probably cancellation? and the entire system just didn't sound right. I may have a gig as such next year and I'd like to be prepared or at least know what to expect. 

Thank you in advance for your time and advise :)

The techniques used are no different from any other directional gradient array, plenty of simulation software around such as EASE Focus etc in which you can have a play to see what “should” happen

You don't want them to act as One (that way you improve the front an back  radiation, quite the opposite), you want them to cancel out in some places and sum in others, and You get this thru the phase relationship. If you

want to focus the bass in the back you could look for "end fire array" bass steering technique. Basically you should find a center frequency you want to focus, let's say 60 hz, then space the subwoofer one quarter of the choosen wavelenght front to back, then delay them (from back to front, so the furthest from truck backk gets no delay, then more delay as you go to the back) another quarter wavelenght. If You don't understand this look how frequencies have a wavelenght that could beexpressed in time or in distance.