If you don't get the battery that is for your car then your car won't run. Your battery has to be a certain size in order to supply power to your alternator, which in turn supplies power to your starter, AC, heat, radio, power locks, power windows, etc. and if you have a DVD player or a stereo system in your car (basically any add on's) then you would need a larger battery to supply more power. Wal-mart is fine to buy a battery, but you may be able to find a refurbished one at an auto parts store, like o'reilly, auto zone or Advance for cheaper then they have them at Wal-mart.