Most people mount the battery on the far right to offset the weight of the driver. Run the shortest lengh ground to the trunk(but make sure the ground is the same gauge as the power). The sape tire well makes a good spot. Make sure to scrape the paint off were its gonna be grounded. I ran 4gauge wire thru the car(i already had it there from my stereo amp. Alot of people(well respected) suggest using big welding cable. Myself and at least 2 others i know run 4gauge and its works fine. In regards to how to mount the batt. Go to pepboys etc. they have batt. boxes that use a strap. to hold the batt box down, Very easy to mount.

98 csvt t-red.. sho-shop intake, b&m, fidanza, spec1 clutch, Torsen, DMD,optimized Y& TB, Brullen, rear strut bar,h&r's,17" konig traffik's. "I say what I mean and I do what i say"