I purchased the Hamman pedal covers from a member of the Z3 Message Board at roadfly.org during late winter 2000
1 Here is the installation procedure I followed:
I purchased the pedal covers used, so I went to Home Depot and got some nice #10 aluminum sheet metal screws for mounting the pedals and about a dozen nylon washers to use as spacers. The screws are fabricated from aluminum and are relatively soft, but the heads have a nice brushed look to them. The rubber nubbly inserts in the Hamann covers protrude a little out the back, so I used 2-3 nylon washers between each cover and the clutch, brake, and accelerator pedals to allow for this.
Take out any floormats that you may have. Though it isn't necessary, you may want to lay some newspaper on the floor to catch the plastic and metal shavings from the pedals. Don't remove the existing accelerator pedal. Removing it will break a tab, rendering it useless.
Pop off the rubber covers from the clutch and brake pedals. The brake pedal is steel. The clutch and accelerator pedals are plastic. I used a small c-clamp to hold each pedal cover in place as I drilled the mounting holes. Be sure you have the correct drill bit size before drilling into your pedals. You may want to test it out on some piece of plastic or metal to see if the screw doesn't have too much difficulty getting through. This is especially important for the steel brake pedal because it is very easy to snap off the mounting screws if the hole is too small. Also, it is very important to take your time drilling the brake pedal. The brake pedal is not flat, but has horizontal grooves like a Ruffle's potato chip. Depending on where the pedal cover lines up, you may be drilling on the edge of a groove - patience is the key.
When fastening the pedal covers, make sure you don't over-torque the screws. They'll break off easier than you think.
The Hamann dead pedal that I have is huge and massive and came with a large mounting tab at the top and bottom. It might have been for a different car, I don't know. I hack-sawed both tabs off and RTV glued the pedal over the kick plate. I did have to remove the left black plastic under-dashboard cover and trim it a bit near the vicinity of the dead pedal.