BYU DFW Alumni chapter is hosting the tailgate on Friday, Sep 6 at 3pm before the 6pm kickoff that evening. They got an amazing location on campus right near the stadium in a large grass area near the Lacrosse field. Here's a map with the venue, stadium and parking options.
It's a five minute walk to the stadium. Fans won't have to battle traffic and find parking at two separate venues. Just get there, walk to the tailgate site then to the game. Fans can find and purchase prepaid parking from a 3rd party site for on campus parking. There is also some game-day parking available, some with access to a shuttle. Finally, when I've gone to SMU games I've just parked at the DART Mockingbird Station for free and walked the 1/2 mile to the stadium. Best thing here is that the tailgate is on the way in.
Feel free to BM or respond here with any questions you have. Link to the tailgate ticket site: