Dumping the exhaust behind the rear axle?

My first setup on my Duster had Thrush header mufflers bolted straight to the headers and ending right there. After about six months of this, the headaches from the noise and having the interior reek of exhaust made me a believer. I put on full pipes with the Duster bullet tips and Hush Thrush muffs and never regretted it.
I literally couldn't drive more than 20 miles or so without getting a headache.