If you send me a link/pic, I can tell you if they are the same crests that I have. Mine fell off (common problem), and I think I still have 1 (maybe 2) crests in the garage from my original set. (I put on a new set.) I'll sell one for $10 plus maybe a buck or two for shipping

Offer good only to Boxsters which is where the other 1 or 2 went that I salvaged. When regluing them, first rough the crest backs and caps up with a grind stone or something, then use a good epoxy as mentioned. I used golf club shaft epoxy. Do the same for the remaining ones you have as well. The glue, obviously, is not too strong.