Where did this come from?

My coworker and I were returning from Stuttgart and saw a decorative license plate on a commercial truck that caused us great confusion:

I did a double take. What the heck is a rebel flag license plate doing on a truck from Ludwigsburg?

I then did a quadruple take. What the heck did it say?

At first I thought it said something in German about "the dead." Then I realized it said "Dern Tooten I'm a Rebel." I actually couldn't understand it at first (sorry, I'm all about the correct spelling and usage folks, and I don't "do" redneck). Uhhhh...the only stranger thing was that the Michelin Man was to the right of that. What is going on?! Why are there weird Michelin Man-loving redneck Germans? Does the driver even know what this means? It's English dialect at a really high level, especially with the non-standard spelling, cultural references, and the flag of a side that lost the battle two centuries ago.