I have a BMW 520i but couldn't start I know it may be a battery but in this car,the battery is no where to be?

This BMW 520i is a M reg (1994).The battery isn't in the engine compartment nor in the back bonnet.Tried and failed to find where the battery is situated.|||i am pretty sure on that model the battery is in the boot or trunk whichever you call it as you look in on the right side with a cover over it that makes the floor level to the sides|||have a look under seats|||Under the back seats. BMW put it there is some years to give the car better balance.|||Look under the rear seat, passenger side. There may be two clips, but just pull up on it.|||Are you sure it's not in the trunk (back bonnet, or boot)? That's where it is in my buddies car. Did you look under the carpet and in the sidewells? If it's not, than the other guys suggestions (under the rear seat) sound good.|||just call the auto parts store. they can tell you where it is.|||well im not know whare your battier is in this particuler modle but im going to presuem that it dose not start on soler power yet so thare must be a cable from your starter and that will take you back to the battier and im thinking that thare is also a alt in the car with witch you can also falow the wires back to the battier or i can just say to look in your oweners mannuel and say read it or you might like to look in the trunk under the seats front and back both sides and look for it some more after all thare are only so manny place one might place a battier in a car and not crate a posable destraction to the driver in the event of it shourting out and in efect blowing up into small pics and not strickeing the driver in doing so for this would heart or case harm to another person or persons and thuse be in rather bad tast in the intrest of safety or others by the car manufacure