Have you left the meter on for awhile, and can it lock in high readings. There may be something going on that happens after the car is well asleep, and even then, possibly at intervals. Surely sounds strange...

Unless you leave that multimeter on for quite some time, you might not be getting the car in sleep mode....

 

Well the car has had the battery hooked up and remained un-driven for 6 days due to heavy rainfall locally. Car started right back up this morning. Difference is last time I used it I took a longer trip than 1/2 a mile or 1 mile .