My trunk mounted Battery is bolted through the far rear longitude frame rails on two parts. The four bolts holding down the battery boxed frame are long enough to exit through the bottom of the frame longitudes with big pressure washers and lock nuts securing them. The battery itself is then secured down with two vertical 3/8 thick Aluminum straps on each side of the battery with a cross over strap bolted on top. Every time the track tech Mafia looks, they want me to set up their cars for them.LOL. The way the battery is set up computes to them that the rest of the car is correct and no more questions are asked.