Steve
By 'offset' I take it you mean an eccentric boss. I never understood the point of this along with flat bottom rims. In UK we have things called bends on our roads which require us to turn the steering wheel to navigate them. If you bought an eccentric boss wheel to get more leg clearance then as you turn the wheel the rim gets closer to you. I suspect theses are a fashion thing along with vinyl roofs & so called privacy glass.
Tim