After reading thru this thread, most of the differing opinions have been covered. But I'll throw my two cents in anyway. The value of getting an MBA, any MBA, is dependent on "why" you're getting it. Career development, entrepreneurial knowledge, self improvement, or any other reasons can all be valid.

From what you've posted, it sounds like your reasoning is you hate your current position, used car lot owner, and want to move to some corporate or office type position. In that scenario, I don't see an MBA helping you. If you move to a large dealership in sales or financing or general management, your experience is much more important. If you are looking to move into some other type of corporate management, an MBA isn't going to help as you'll be competing against 20 or 30 somethings, and you're going to lose that contest.

However there is one situation that may fit. An investment banking professor said something in one of my MBA classes that I've never forgotten. "Brains are cheap. The person who can sell gets paid." If you're looking to take that MBA and start another business, any business, it'll be beneficial. Start a software company, make a better pillow, whatever; it doesn't matter. An MBA will give you the ability to look at any opportunity and break it down into simple dollars and cents. If you can sell, you can sell...period. An MBA will give you the tools to find more creative ways to separate customers from their money.

Bottom line is you have to look at why you want to get it and what you're going to do with it after you have it.