here's how
my friend at the paint and body shop uses 3M Scotch-Mount Double-Coated Acrylic Foam Tape. i also use one of these at my sign shop and the one i use is gray/.045 inches thick Part Number 051131. the actual large # on the tape container is 06383. sometimes my friend uses different varieties and numbers of this tape but he ALWAYS uses the 3M brand only. often i have seen him use this type of tape in a brown color but i do not know what the number of that tape is.
it states on the container that the Applications are: accessories, body side moldings, claddings, door edges, emblems, fascia rub strips, garnish moldings, interior trim panels, rocker panel moldings, pillar covers.
he covers the entire rear side of the emblem with the tape and then uses a single edge razor to cut the foam to the exact shape. he then meticulously cleans the car surface paint where the emblem is to be installed with a paint reducer (if it is not brand new paint) followed by a cleaning with isopropyl alcohol and inserts the pins into the holes and pushes the emblem hard against the car panel. of course, he removes the paper from the tape before he installs it on the emblem and the same thing before on the car. you want to avoid getting fingerprints on the glue surface of the tape or where it is to go on the car since the oil in the fingerprints effects the bonding capabilities of the tape.
the tape is available from any car supply outlet where they provide paint for body shops and is rather pricey. many retail discount auto parts houses have it in small rolls. USE ONLY THIS STYLE ACRYLIC FOAM TAPE SINCE IT IS VHB (very high bond) and is made to be outside. DO NOT USE THE WHITE FOAM TAPE AVAILABLE AT HOBBY SHOPS, HOME DEPOT, ETC. the white tape was not designed to be outdoors for long periods of time. if you go to any decent paint and body shop and do a little kissing up (after all, your car is about 20 years old and at some point is gonna need some work) they will either sell you a little or even give it to you. ASK FIRST if you can pay for it or buy some. i have seen Jim actually clean off the back sides of customers and potential customers emblems, apply the tape and then tell them to get outta there. i have never seen a call back on anything he has done.