Strengths
Looked really different from other cars when came out and sold well. Car not geared towards one particular demographic of people. Heavily promoted and used in the movie Italian Job Light weight and probably relatively fuel efficient. Wasn't it made by BMW, a reputable company
Weaknesses
Seems as though it was just a fad. Don't see the car selling as well as it did when the car debuted
Opportunities
Sell in countries where gasoline is expensive and where need a small car. Japan for example you want to drive a small car because parking is hard to find and can only accommodate small cars.
Threats
Other companies are coming out with mini cars also. I heard one company is coming out with the for two, a mini car that seats two people hence the name.