[mr48chev]

I have no idea if they would rattle or not. You see photos of street rods with them once in a while but to me they aren't practical. The remote boost points would be an absolute must if you had them though. My BMW 528 has the battery in the trunk, absolutely no place under the hood to hook jumper cables and the only place on the engine means that you have to jack and block the car up and slide under it and hunt for that spot to hook the cable to. When the battery is dead, the trunk won't open and the other way to jump it is crawl though the back seat into the trunk and hook jumper cables or the charger to it.

With that I would really question the wisdom of putting the battery under the cab in a a spot that required jacking the truck up to have any access to it. There are plenty of batteries that are designed with setups that allow them to vent under the floor of cars when they are installed under the back seat. The battery for a 2000 Cad Deville DTS isn't very tall but can be had in a pretty high amp rating. Same with one for an Audi 5000 from the 80's. One could be placed in a box behind the seat and be out of the way and out of sight but pretty easy to access when needed.