Exactly!! I tried doing MBA part-time while doing job but found finance a boring subject. Mathematical problems finance were interesting to solve but I found accounting horribly confusing...the balance sheet...oh!! I had to give-up for other reasons, but I was happy that I got rid of that...after all I like to spend time with electronics during that extra time became available...
But I agree that to be a good engineering manager or an entrepreneur, once should have good understanding of finance.
I actually though it would be a good idea to get an MBA part time.
When I finsihed my engineering degree, since I finished so far back in the pack, I decided that I wouldn't be a good engineer. I then did an MBA. It seemed to me an engineer as a manager was a good plan since a) you could get further organizationally and b) there were always managers who needed to understand what the engineers were doing.
Circumstances conspired and got me into engineering rather than management, and I have only recently moved part-time into management.
I actually thought it would be a good idea to get an MBA part time. My best classes were economics and the worst were accounting and business law. Coming from an engineering background, I found the whole cencept of law illogical.