I mentioned in the other post the BMW is giving me $500 towards Mini accessories. Besides winter mats and a trunk liner, what have other owners found useful? I have enough shirts.
I'd look at the trunk liner before deciding... I'm not thrilled with mine. With the trunk floor in the lower position, the liner doesn't fit very well. There's no cut out for the floor handle, and you cant tilt the floor up because the mat hits the plastic pieces on either side that support the floor (where the pivots are). Do you have roof rails? The roof rack could be a good option.
After looking at the site, the roof rack seems to be the only functional item. Too late on the mats. I told the salesman to order the front and hatch (I will take the rears from my 128i) when I was picking up the car.
Sun shade is a good bet. If you're getting the power spokes, the wheel balancing counter weight would be good to have. https://www.ecstuning.com/b-genuine-mini-parts/adapter/83302471407/ You could get a visor for the passenger side to replace the grab handle. Some people prefer the handle, but I like having a visor there better. I might think of more later.
I have found the roof rack and it is quite useful. At about 60 + mph there is a bit of noise and efficiency reduction from the aerodynamic drag. But given that my usage rarely includes freeways and often includes kayaks, it works for me.