Volvo: Help my 1996 volvo wont start, volvo dealership, market radio

Question
Yes, I was thinking the same thing.. but when brought into volvo they said they needed it to not start to see what the issue is. Is there a way to diagnose this w/o waiting for it to die again? I was reading about attaching a device and then removing the equipment.. This is very frustratng.. car is very good except for this..
-------------------------------------------
The text above is a follow-up to ...

-----Question-----
I have a 1996 volvo which runs great - the only issue i have is that if we don't drive it everyday the car won't start - no cranking nothing, dead. We had a major tune up, battery tested works great, and alternator fine. Volvo dealership could not diagnose the problem due to car starting fine after we jumped it. I think it's an electrical problem slowly draining the battery. Any idea where to start? I don't want to spend alot of $$$ - also it has like 200K miles on it.
Thanks!
-----Answer-----
Lisa,
Some things that drain the battery are lights in door jamb, glove box, trunk. The relay for the air pump if equipped, after market radio, and the alternator itself.

Answer
Lisa,
How about in the dark of the night you look through the crack in the doors to see if the small red light is stuck on and also the glove box. Unplug the air pump relay.  Turn off the trunk light and see if that will help. I do not know what is meant by "attaching a device" before removing any equipment.