Re: Car clock slowing down...daily.
I had the same problem after I had a DVD player (the touchscreen sort with GPS) installed by a site sponsor. After a few months, I noticed that I was "losing" 1-2 minutes a day before the problem worsened to 4-5 mins a day. After I have that removed, I had no issues with the lost minutes. I understand from a bro that it is probably due to a wrong connection during set-up.
Like yours, the system shouldn't be draining battery while it's parked but somehow I was "losing" minutes.