Muffler location?

[muddpile]

I am still thinking about making my exhaust exit just in front of the rear wheels, angling outwards with the tips just outside the body like an AAR cuda. I am wondering a couple of things before I do this, however:
-Where in the system do I put the mufflers?
-Will this harm my tires or paint?
-If I use flowmasters, will it be really loud inside the truck?

Here's a pic of what I'm thinking, on a car, but same idea.