Personally I think the options of mats currently (and previously) available for the Z3 is very very poor. I have a set in my M which I bought from a forum member when he sold his Z and they are unique only because they are trimmed Estoril blue and have "Z3M" on them. Whilst these are the most unique mats i have found, I still think they could be so much better - the material is universal, the pile is crap and the texture is that of bad bog roll.
The mats in a new BMW are thick. They have BMW (or //M) sunk into the pile. They are quality. The quality and concept that you see in new BMWs is basically copying the concept of the mats and trim that were standard in premium cars 10-20 years ago. This is the level of product we should now be expecting to be retrospectively available in my opinion.
At the end of the day these aftermarket mats that we are all limited to buy are essentially universal materials and styles which are only specific to our cars due to the fact they are shaped to fit the Z3 and can have the trim in a bespoke colour - in other words the mat you buy for your Z3 pride and joy will essential be the same mat that dippy Doris buys for her skoda skip that she has had for 20 years