Assult and supply truck.

What this is a small based vehicle that you can go out and get supply's.

The vehicle that you use is in the link. The Gator

Now is when building come's in.
Make a steal mesh around the entire vehicle with two doors in the front and a hatch for the back so you can put your supply's that you get. Put some type of glass around that will not break and can protect you from the inside. (I'm not sure what would work the best for a mesh around the gator but something that would hold and make you safe inside of the gator from the zombies)

With the wheels so vulnerable, Put steal planks on the side of them so nothing can touch them.

{Weapon defense}
Well Remember the Nail Boom? Grab a couple of those for when things get heavy.
There will be a hatch on the top of the drivers seat where you can throw the Nail Boom out.
Around the sides will be barbed wire.

I'm not sure what else you can add but that is something good that all of us can discuss.