What usually messes up is the loading/switching mechanism. If it is sparatic I would say it's about to be broke for good until it gets fixed. When I worked at chuck's we sent as many off for repair as we replaced. It was usually around $250 for repairs and about a 2 week down time. Then 3 months later half of the repairs would come back and they were off for another two weeks.

I'm the same way, as soon as I buy a truck/ car it's getting audio as soon as I sign my name. My last 4 vehicles have gone straight from the lot/owners house to the exhaust shop, then to the stereo shop, then back home for install. Except for me black 02, I was lazy on it for a couple weeks until I got tired of not having my iPod and remote start.