My understanding from some of my Iraq war veteran friends is that Humvees lack adequate undercarriage armor and they aren't designed for/can't be properly modified to carry the proper armor. There are newer ones with beefed up engines and suspensions but it's kinda like deciding you want to jump ramps/obstacles in a vehicle and trying to supe up your pickup truck rather than building a race truck[1].

MRAP is not a single vehicle but a class of vehicle[2]. The name kind of says it all: Mine-Resistant Ambush Protected.

My friends were stationed in bases inside Iraq and never really had to do any "off road-ing". They had to convoy between different installations within the country. Typically on poor roads but roads none the less. They worked with the Iraqi Defense Force to transport prisoners, supplies, etc.

This[2] is the kind of stuff that they were scared to death over and why they wanted MRAPs. Apparently Humvees don't take kindly to those sort of explosions or rockets, mines, IEDs, etc.

[1]My buddy and his friends do this with their Tacomas and regularly blow out suspension and drivetrain parts. CVs especially. This is no fault of the Tacoma, they are NOT designed to jump large gaps at speed like a Trophy truck.

[2]http://en.wikipedia.org/wiki/MRAP

(GRAPHIC)[3] http://www.liveleak.com/view?i=02b_1189545597 (GRAPHIC)

Edit:

That said, I have NO idea why they'd want these in a city other than the bling/super Ninja Robocop ego factor. Using the same SWAT vehicles as the local PD seems like a better choice since the support network would already exist.