i have created an 8 cell evo truck. it is crazy in compared to the 4 cell. in the hummer i mounted the holder under the stock batteries with double sided stickey tape. (the hummer must be lifted.) my buddy built an f-150 with 8 cells. he put the holders in the bed. we race our trucks on a prepared dirt oval, and they have no problem getting up and going. i hope this can help or inspire some of you mother truckers out there