hi
if you have a multi meter you need to check what battery leakage you have, the current drain when every thing is off
also the car is suppose to go asleep after 40 mins, this can be stopped some times from a faulty device, like the ignition switch, theres a flap that shuts once you pull the key out
you could connect a multi meter in series with the battery and see what the current drain is and pull fuses till it drops to a correct level
may be worth also checking your battery is charging correct, should be above 14 volts with engine running, alternator might of packed in
current drain should be as below
cheers
joe