I've always had a second car, be it my own or through the other half, mostly we both have normal cars, and then i have a 90/110/landrover thing as well!!!
I did it because of my commute, to do the 100+ miles each way in a 90 would have killed me and my bank balance so i opted for the car, its also better for nipping to the shops, picking up the kids or taking the in-laws out for lunch, these days im down to a practical A3 (well kinda practical)for day to day, the misses' golf estate and the d-lander.
It costs a lot to run a second car once you add it all up, insurance, purchase, running, tax, fuel - probably more than filling a thirsty 90 on a reghular basis but there is more to it when you consider comfort and speed either end of a long working day.