The "shift paddle mod" is pretty straightforward. You need a steering wheel from an E46 M3 with the SMG transmission. On the particular wheel I had, a previous owner had swapped out the standard plastic shift paddles for ones made from carbon fiber. They had no effect on function - they're purely cosmetic. If you're modding a pre-facelift 4.6is or another X5 with the Sport package, the E46 M3 steering wheel uses the same airbag. So that's a direct swap. The only other part you may need is the slip ring, or "clock spring" assembly. This is the interface that connects the various buttons on the steering wheel to the car's electrical system. I say you may need to replace it because yours may or may not have the electrical connections for the paddle shifters. My X5 did not have the connectors so I had to buy a new part. I waited until I caught one on sale and got it for around $130.

Once you have the parts, the only thing you have to do is run wires from the back of the slip ring down to the center console and tap into the wires for the Steptronic shifter. IIRC, there are 4 wires on the connector and the two in the center are the ones to tap into.

The finished result looks like a factory install. Many people claimed that this mod eliminated or reduced the slight lag when using the console shifter to manually shift. I didn't notice any difference, but it is a lot cooler to use the paddles!

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2002 X5 4.6is - Imola Red/Black (Sold)
2001 740i M Sport - Anthrazit Metallic/Black (Sold)
1998 M3/4/5 - Technoviolet/Dove (Sold)
2003 Z4 3.0i Sport - Sterlinggrau Metallic/Black (Sold)
2009 Mini JCW (The Wife's)
2015 i3 REx - Arravani Gray/Tera World (Daily Driver)