Battery drain, electrical problems

Imagine this. Another problem with a 2001 Jetta (4-cylinder GLS) and a parasitic battery drain. Details below, and any insight you can provide would be helpful.

Condition and Tests

* car killed three batteries in two years (no problem starting in summer, but winter breaks them).

* charged existing battery to 12.4 volts, disconnected it, and then reconnected one week later to reveal 12.4 volts. (should be 12.6 at full charge, sure, but only got to 12.4)

* connected battery overnight, 12.4 volts dropped to 11.8, no start.

* same result as above with brand-new battery (including 12.4 volt limit on full charge and subsequent voltage drop).

* multimeter says alternator charging normally (steady reading of 14.5 with car running, tested on both batteries)

* set multimeter to 10 amps, and readings jumped around - 0.5, 0.85, 1.1 - then quit to 0.0 with 10-amp fuse blown (verified with continuity test on fuse pulled from multimeter).

* after three days with battery disconnected, placed a 12-volt test light (0.4-amp draw) in-line, and pulled everything I could think of one-by-one — all fuses (battery fuses and interior panel), Monsoon audio (radio, amplifier, and CD), and alternator — but test light (rather bright) would not go out.

Observations (some odd)

* radio retains presets, even with week-long battery disconnect. (unheard of, in my experience)

* CD player, a usual suspect, is factory but installed after market (and removing it didn’t make light go out)

* test light glimmered - brighter, dimmer, brighter - not a steady consistent light.

* with fuse 42 (radio, 25-amp) removed, test light would glimmer in sync with loud clicking in the dash behind the odometer: louder clicks = brighter light, quieter clicks = dimmer light.

* glove box, trunk, and interior lights go out when glove box or trunk closed and/or car turned off.

* all auto locks and windows work properly, but can hear what sounds like a window motor trying to wind when doors are unlocked (not CD player).

* daytime running lights stay on with parking break engaged (should not happen) and key sometimes difficult to remove unless placed in ‘park’ forcefully. (this may be a separate issue)