Sorry guys, I was mistaken about the velcro for the Weathertech liners.
My hubby who installed the mats said that he did 'screw in' the mat holder on the driver's side only. He said that there are two plastic t-shaped areas in the carpet on the driver's side floor nearest the seat which are meant for this. You simply push the hardware provided by Weathertech into this plastic area and screw it in by hand. It takes seconds and there are no tools or drilling involved!
I assume that this process is the same whether you buy the Weathertech or BMW mats. The only negative if you have the M-sport package is that the pretty dead pedal is partially hidden by the mat.
Here are some pictures of what the mats look like in "real life"!