Step by step f80 M3 carbon fiber trunk spoiler installation 

I would do everything possible to ensure none oozed out and required being wiped away.

Sounds like we have the same spoiler and was curious as to what you did and how it held up over time? Currently debating betalink and 3m auto grade tape

Good question. You have some time before it sets so hard that you can't move it. But I'd strongly recommend that you do all that you can to have it as dummy proof as possible when the time comes to seat the part.

The epoxy will not change the profile of either's mating surface but it will fill in any gaps *far better* than any double-sided-tape will.

@vSApophis double sided 3m heavy duty tape works just fine even at really high speeds

In regards to the PPF, yes. The logic is two-fold: 1) I do not like to rely, mechanically, on double-sided tape, and 2) there is about a zero % chance this way does not hold equal or better with fewer drawbacks (such as how awful removal of double sided-tape is on paint or in my case the satin PPF). The downforce created is not exclusively downward against the bonding agent/decklid. There is also a lateral push. In that way it's not purely about downforce working *with* the spoiler to the body. In the case of the way I used an intermediate PPF layer, it's simply not going to peel away or come loose. I am now sitting with more than 8,000 miles on this installation with it having experienced freezing and wildly hot/humid weather countless times and she's holding up well. And when it's time to remove the spoiler I guarantee the process will be better than dealing with double-sided tape. With all of that said I am not saying someone's a fool to do it with just DST. Different folks, different strokes and all. But this is my preferred method and how I've done it on other client's cars with good success. The reversability of this process is a nice icing on the proverbial cake too. :)

this is a more cleaner and permanent way to install a spoiler. It looks better in person with glue than tape

3m tape doesn’t do the same thing piss me off I’m ripping off your spoiler lmao

3m tape is coming off for me tbh bc its so hot