I've been down there several times and I've also seen the lights in the rearview mirror. Hubby swears it is an optical illusion and that somehow the lights from the main road are reflected. He's explained it, but I'm still not 100%.
As for the roar -- check out my post in the Enigma Attic section. Even though Bragg road is in Hardin County, it isn't far. My mother in law, who lives next door to us, has been hearing odd sounds for a few weeks.
A fellow by the name of Rob Riggs wrote a book several years ago, called "The WildMan of East Texas" in regards to East Texas Bigfoot sightings, black panthers, and the Bragg Road lights. It seems that sightings of Bigfoot have occured pretty frequently in the area of Bragg Road. You may have had an encounter! It is an interesting book, some of his theories are a little "out there", but interesting.
On a much less paranormal, but still scary note, rumor has had it that some local goofball who kept exotic animals unleashed his African lions last year to avoid getting caught by authorities. I don't know of the truth to it, but last year there were sightings by several folks, one of which was a hunting guide who was able to identify them. A friend of ours had one of his pet goats nabbed by one -- he actually saw it late at night in his pasture. I haven't heard of any sightings of them in months, but it is plausible they could have gone into Hardin County.