Reddragon - go to the back of the class - a Z4 is a two door, two seat, sports convertible - always has been always will be - IT'S THE LAW !!
As to whether you will fit Joe - I'm sure the Z4 is a bit longer than the Z3 and the seats are fully adjustable (not just up or down but a long way back) you might be better off seeing if they have an auto as opposed to a manual as it will keep your left leg still instead of flexing and bending it to use the clutch.