Side skirts
The factory side skirts are relatively deep and feature an interesting feature line. However, they're a little dull. Whereas, the BMW Performance replacements have a far more interesting (fake) vent in the rear of the skirts, and an elongated scoop leading up to them. They definitely add more interest to the side of the car and create a more sporting profile.
Again, fitting takes minutes and requires few specialist tools. You will need to pop several plastic clips, so patience will be rewarded.
 To remove the factory side...  To remove the factory side skirts, start by taking off the sill covers. Use a forked tool to lift the edge of the cover and prise the plastic pins out of the body. Also remove the pin retainers from the body; these will be re-used |  There are 10 Torx screws under...  There are 10 Torx screws under the car and two bolts by each wheel to undo |  Using a plastic wedge so not...  Using a plastic wedge so not to damage the paint, prise the skirts away from the body. There are more pins behind the skirt, which you must release |
 Don't try to rush this part...  Don't try to rush this part or you could leave broken pins and clips on the car that will need to be removed and replaced |  The black plastic sections...  The black plastic sections and round holes all house pins that are released as you remove the skirt |  The holes in the rear of the...  The holes in the rear of the BMW Performance skirts are filled with supplied plastic mesh pieces. These are fixed using double-sided automotive tape. Use the supplied adhesive promoter on the plastic part to ensure it sticks properly |
 Push the vent piece into place...  Push the vent piece into place and apply pressure. It should stick instantly |  The new skirt fits almost...  The new skirt fits almost exactly the same as stock |  Apply WD40 to the holes and...  Apply WD40 to the holes and clips along the side of the car and push the new skirt into place. |
 Use the supplied push-pins...  Use the supplied push-pins in the underside, replacing the OE bolts and screws |  Use the supplied push-rivets...  Use the supplied push-rivets in the upper section of the skirts |  Push the sill cover back into...  Push the sill cover back into place using the original plastic pins, which hopefully didn't break during removal |