it was easier to work with 2 seperate peaces instead of onebig one..and also if somethig happens to one side of it i dont have to replace the hole thing just the one side as for the NHRA comment every where i read it says it has to be at least 1/8th inch thick witch mine is doesnt say any thing about design requirments or any thing like that but not really planning on getting to hot and heavy with santioned racing our racetrack offers FNSR witch you just pay the fee they run you through tech (mainly looking for fluid leaks seatbelts checking tires and brakes) and away you go they run the full tree and its timed..so thats good enough for me