Clean both surfaces properly, and the 3M tape should be more than enough. I've used it to hold on body pieces in a few different scenarios.. one that I still see every day is the front bumper on my advisor's car. The bumper skin itself uses the factory mounts, but all of the stuff that came stuck to the original I mounted to the replacement with 3M tape. That was 4 years ago; he drives it year round and puts LOTS of mileage on it.

As with most jobs of this type, prep is everything.

Edit: Just noticed this post:



If that's the case, epoxy it. The only reason to not use epoxy is because it's not something that's reversable.