UPDATED LINK TO PICTURES:
Here is my comprehensive DIY for the BMW Performance Carbon Fiber Spoiler using 3M tape on a 2010 E90 M3. The instructions should be the same for an E92 M3.
NOTE: There are TWO different BMW Performance CF spoilers for the E90! The version I got is BMW Part No. 51-71-0-411-575, and is actually designed for a regular 3-series, but fits the M3 just fine. This style of spoiler installs in the OEM location AND on the curvy section of the trunk. When installed, this type of spoiler looks like the Vorsteiner trunk spoiler.
However, the other style of CF spoiler, which was designed for the M3 in mind, installs ONLY on the OEM location (does not mount to curvy portion of trunk) and looks just like a bigger version of the OEM in carbon fiber. The part number for this spoiler is 51622159805:
MORAL: Be sure you order the CF spoiler for the look you are achieving. Either one will fit the E90 (M3 and non-M3).
First, here are some pictures of my spoiler (BMW Part No. 51-71-0-411-575). I was very surprised at how light this thing is. It was liking holding a piece of styro-foam.
Yes, the spoiler is hollow on the inside.
Supplies (not all supplies pictured):
3M Super Strength Molding Tape – Part No. 03614 – 1/2” x 180” (AutoZone)
3M Super Strength Molding Tape - Part No. 03616 – 7/8” x 180” (AutoZone)
Scotch 3M Painter’s Tape – 2” width (Home Depot)
Exact-O Knife (Hobby Lobby or any crafts store)
Goo-Gone (Home Depot)
Quick Detailer Spray
Plastic Packing ribbon ~ 4 ft. (save it the next time you purchase an item that comes in boxes that is wrapped in the plastic ribbon). This ribbon was from the tires I ordered. If you really need one, go visit an Office Depot or Office Max and ask if they have assembled any chairs recently and ask for the plastic ribbon that’s usually wrapped around the box of the chair.
ASIDE: The plastic ribbon is also great for removing the M3 trunk emblem as well as the trunk and hood BMW emblem.
Step 1: Remove OEM spoiler. Using the plastic packing ribbon and your bare hands, wedge the ribbon underneath the OEM spoiler and the trunk. In a sawing (back and forth, back and forth) motion, work your way from one end of the car to the other. Use your own body weight and pull and saw back and forth. I was able to remove the OEM spoiler after about 15 min.
Here is what the plastic ribbon looks like after you are finished removing the OEM spoiler. It takes a beating. Forget dental floss and fishing line, which will be even more stressful on your bare hands. The plastic ribbon is the best way to go as it is strong and has a large surface. The plastic ribbon, with its flat edge, essentially acts like a plastic knife to allow you to cut off the OEM tape.
This is what's left of the plastic ribbon. It takes a major beating.
This is what the OEM spoiler looks like when removed.
Sep 3: Eliminate OEM tape with Fingers. Use your fingers (thumb preferable), rub back and forth and roll up the residual OEM tape on your trunk until it forms mini balls. This gets pretty painful very quickly as your fingers become heated due to all that friction from rubbing. Do a thorough job and remove all large masses. Step 4 below won’t work as a substitute for this step. Your fingers are the best tool for the OEM tape removal.
Step 4: Eliminate OEM tape with Goof Off. Using Goof Off and your micro-fiber towel, apply Goof Off on the towel and clean the trunk to get rid of the remaining glue from the residual OEM tape.
Step 5: Clean trunk area. Using your quick detailer spray, spray your trunk area and wipe clean with micro-fiber towel. Let your trunk completely dry.
I accomplished Steps 1-5 in 30 minutes.
Step 6: Tape Underside of CF Spoiler. Apply 3M tape to underside perimeter of BMW Performance Spoiler. Use the 1/2” tape for the short left and right sides. Use the 7/8” for the top and bottom long sides You’ll notice that the spoiler in some parts has a slight lipped edge to it. When apply the 3M tape, put it as close to the edge as possible without covering up the lipped edge. When it comes time to wrapping the corners, use scissors and estimate slightly more tape than you need and trim the tape. With the Exact-O knife, trim off any excess tape as close to the corner as you can.
I first used the 7/8” tape first along the top and bottom perimeters of the spoiler. Yes, after applying 7/8" tape on the perimiter, there will be excess tape on the perimiter of the spoiler itself. I did not use the Exacto-Knife to trim this excess as I wouldn't be able to get perfectly straight lines. Thus, I left this excess alone.
VERY IMPORTANT: When apply the tape, keep in mind that it is highly flexible. You must stretch and pull the tape with a bit of force to make sure you get a nice thin and tight layer along the spoiler perimeter.
Next, use your 1/2” tape and again, apply it near as close to the edge as possible (there is no lip on the left and right edges of the spoiler to use as a guide). Apply 1/2” tape OVER-LAPPING the areas in your 7/8 “ tape and trim excess off with scissors as a general estimate.
Now that you must be precise, using your Exact-O Knife, trim off the excess overlap As pictured below, you can see where I trimmed the excess overlap.
After you are finished, your spoiler should look like this with tape in all the areas. Notice how there is no longer any overlap in the tape. Go through with your fingers along all edges of the tape and press down to make sure the tape is fitted tightly.
NOTE: At least on the E90 non-M3 spoiler I have, there are two square indentions in the spoiler. I don't believe these indentions are present in the M3 spoiler. I believe these indentions are functional, because it allows any water/moisture that has gotten caught in the spoiler to drain and evaporate away. Of course, it can also be a source for water to get into the spoiler (but not likely as the holes point straight down once the spoiler is installed). Regardless, apply your 3M tape around the indentions.
No overlap of tape.
When you flip the spoiler over, you’ll notice you cannot see any tape sticking out. If you do, using your Exacto-Knife (and looking at the underside of the spoiler), trim off the excess.
I accomplished Step 6 in 30 min.
Step 7: Clean trunk area again. Wipe down your car with the quick detailer and micro-fiber towel again and allow to dry.
Step 8: Test Fitment of CF Spoiler. Do a test fitment by placing the spoiler on the trunk. It will almost auto align itself because it’s molded to fit perfectly. It’s easy to make the mistake thinking the spoiler sits on top of the trunk like OEM. It does NOT! This spoiler sits at a 45 degree angle from the trunk.
When aligning the spoiler, note how much space there is on the left and right edges so that you know how its centered.
Step 9: Prepare to Install Spoiler. Remove the back side of the 3M tape from the spoiler using the Exact-O Knife. Trust me, your finger nails are not precise enough to remove the back-side of the 3M tape. Using the Exacto-Knife, you can pry it up and peel it off with your fingers easily. If you did a good job taping in Step 6, you should be peeling off only 4 strips (2 long strips of the 7/8” and 2 short strips of the ½”).
Step 10: Aligning Spoiler. Holding the spoiler on the far left and right, gently lay the spoiler (do not press down) on top of the trunk where it should be. Using your eye-balls, make sure the spoiler is aligned both horizontally and vertically. If you make a mistake, simply lift the spoiler upwards and re-align. The far left and right edges should have the same distance from the edge of the CF spoiler to the edge of the trunk lid.
Step 11: Pressing DOWN on Spoiler. Once you are satisfied with the placement, press the spoiler down on the top edges first (edges nearest to rear window) in small increments until it is all press down.
Step 12: Press Foward on Spoiler. Press forward (towards the car) on the rear edge of the spoiler nearest the license plate in small increments.
Step 13: Eliminate Gaps in Corner Edges. Press down and firmly on the four corner edges of the spoiler. This is the area where most installs go awry and have gaps. Be sure you have sufficiently taped these corner edges back in Step 6.
I accomplished Steps 7-13 in 15 min.
Step 14: Hold Spoiler in Place. With the 2” wide painter’s tape, tape the spoiler VERY TIGHTLY to the car. Tape the top portion of the trunk first and work the tape to the rear. Notice how I purposely left air spaces in the tape on the rear just under the spoiler. This is how you achieve that tight fit.
Step 15: Hold down Corner Edges. Tape down the four corner edges completely (don’t leave any air spaces this time).
I accomplished Steps 14-15 in 10 min.
Step 16: Allow 3M Tape to Melt and Bond. Park your car out in the sun for 2 hours.
Step 17: Remove all blue painter’s tape.
Step 18: Stare at your new spoiler and smile. Good job!
Final Thoughts: I had great success using the 3M tape. I do not recommend using Betalink as I've heard horror stories of it getting all over the car. Also, once the spoiler is installed using Betalink, it is permenant. Well, you could remove it, but you'll probably end up snapping your nice CF spoiler in half (so much for trying to resell). As for the the length of 3M tape, you can get away with buying the smaller length (60") of the 1/2" width tape. For the 7/8" width tape, you definitely want to buy the 180" as you will use a lot of it. The roll should be enough for two applies in case you mess up and want to redo parts of it.
Fear not that this thing will be prone to blowing off at highway speeds or theft. After the spoiler is installed, if I grab the spoiler and wiggle, the spoiler does not budge...but the entire back end of the car starts shaking. It is stuck on there pretty tight.
No gaps. Can't see the 3M tape. All edges and corners are sealed.
As you can see with BMW Part No. 51-71-0-411-575, this style of spoiler installs on the OEM location on top of the trunk as well as the curvy portion of the trunk and justs out at a 45 degree angle (very Vorsteiner-like styling).