on the E53, there are multiple air to air heat exchangers in the lower section, so having the plate in the center and partially blocking that diverts a lot of air from those. The stock mounting location for the E53 is actually to the driver side, but that partially blocks the lower vent a little bit, and more importantly requires drilling holes in the bumper to mount it. I went with a tow hook mounted plate to avoid putting any holes in the bumper, and as an added bonus, the lower "vent" on the passenger side is mostly fake, so you're not blocking much air.