[DuSh]

Used 3M double sided tape and Auto/Marine RTV Silicon - within first 15 minutes I saw my roof spoiler in the rearview mirror flew away. Thankfully no one was behind me at that time and spoiler landed on a sidewalk scuffed, but not broken). Going to wrap it in black CF, but not sure what to use now?

Betalink? Tiger glue? Windshield adhesive glue?

[Billfitz]

It should have held, if you properly prepped the car first.

[M2Rush]

You can just use 3M moulding tape available at any hardware store or the Scotch 30 lb mounting tape. Most importantly, like bill mentioned, it has to be well prepped. Use rubbing alcohol(isopropyl is best but any will work as it is made to completely evaporate taking along any traces of oil with it) to clean the surfaces of your car and the spoiler, this will remove all traces of dirt along with any waxes/sealants you may have on. Once that is complete you need to make sure your mating surfaces are not cold to the touch, at this time of the year it is best to heat both the vehicle paint and blast some heat along the tape as well. Once completed, make sure you use some type of wax to protect the parts that were cleaned with alcohol.

[M2Rush]

Search google for instructions, Brain from Kies motorsports recently did an updated video which may help you but it's for the rear spoiler. The concept is the same though.

[Billfitz]

I use 3M adhesion promoter as well.

[rlmesq]

Originally Posted by Billfitz

I use 3M adhesion promoter as well.

+1 on this stuff. My paintless dent guy (who is just amazing) told me about the stuff. Just make sure you don't get it on anything but the mounting surface of the spoiler or you'll never get it off.

I've had great luck with 3M 06384 Automotive Acrylic Plus Attachment Tape. Just copy & paste the name above into Amazon. The 3M trim tape isn't nearly as secure.

[7iM3less]

Make sure your using NEW 3m tape from a retail store. The tape they give you when you buy the aftermarket spoilers from China is hit and miss. I had tape come with my spoiler and side skirt extensions and it was garbage. I ended up peeling it all off and applying new tape.

[wdeerfield]

it also comes down to placing the tape properly on the spoiler where it makes the best contact with with the glass. I had the sides lift up because i put tape in the center. Id recommend putting tape on the entire bottom except where it overlaps the rubber seal of the window and the "high" spot in the center of the spoiler. This will allow it to sit flush on the glass better and not lift. I also recommend putting books or some weight on the edges along with some painters tape to hold the spoiler down overnight. remember, it must be above like 60 degrees for it to properly bond too.