If you go to Murray's or another similar car parts store, there will be two products. An emblem "adhesive," which is a glue, and these 3M emblem strips. Stay away from the glue. What if you mess up, you're screwed? No thanks.
I've used the 3M emblem strips with no problem. It's not cheap, expect to pay at least $5 for a small roll of it. You can easily cut it to shape, and yes, it stays on no problem. I've had an emblem on my car for over a year now, and it's as rock solid as the day that I put it on.
Because the "Riviera" emblem is very complex, you are going to have to be patient with cutting your 3M emblem tape. Use multiple pieces if necessary. It will be worth it.