Hi, I just ordered my 2008 c6 convertible today and one thing the salesman told me is bothering me. He said that I have to start the car every 21 days or I will have to call GM to get it going again. Whats up with that? Would haveing the battery on a trickle charge prevent this? I don't drive the car in bad weather and it may have to stay in the garage for a few weeks at a time.  

My 2008 c-6 coupe has been sitting since November 22.  It has a total of 289 miles on it.  My battery went dead from disuse.  I trickel charged it and it started right up.  Any time a car sits for a month or more, it may lose its battery charge.