With the way the E46 roof is constructed, it would be easier to peel the whole skin off and replace it with a slick top skin, but if you're going to that much trouble, a carbon panel would have been the way to go surely.
The "Hand-Stitched Complete Leather Interior" option. Normally only the centre section of the steering wheel is leather wrapped, with the wheel remaining in black. Could be an individual spec seeing as the whole wheel is the same colour.