I just installed BMW OEM all-weather mats front and rear after looking at both Weathertech mats and Weathertech liners. I have a Weathertech rear cargo mat ordered for the back.
I prefer the OEM velcro mounting in the front and BMW supplies the same type of velcro disks (and full size mounting template) for the rear mats.
'13 X5M - carbon black over black • BBS SV • "it's our truck"
'13 X5 35i - alpine white over black • X5M wheels & tires • "it's our car"
'12 650 vert - alpine white over cinnamon • 6 speed manual • Münich delivery
'11 Z4 - mojave over beige • 6 speed manual • Münich delivery
...and a bunch of old English motorcycles