if you take you car to a good muffler shop they can do it with the battery in the original place. I have a 36 pickup with duel exhaust ,and the battery in the stock place. one day I was driving my pickup and stopped at a store to get something, then came back to my truck. there was a puddle of water in a weird location , right under the floor board, where your feet rest. so I climbed under too look, the battery had slid over to the header pipe and had a hole melted in it, bad movie! then I figured that I better get home. after I got home I left the motor running pulled the floorboard and removed the battery and gave the underside a baking soda bath. what I ended up doing is I took some angle iron and mounted it to the side of the battery box and sliced some 1/4 fuel hose to protect the battery. other then that trouble what was my own stupid fault I have had no trouble with the battery