The riveted metal Mugen badges are commonly found on front lips and aero pieces. These badges were included on many previous-generation, discontinued Mugen body pieces that circulate the secondary market. Given enough time, miles and repaints, the badges have become one of the only remaining indicators to tell a genuine apart from a replica body part. There are few ways to spot a replica/fake metal rivet badge:
1. Packaging. If the emblem does not include the proper package (or no package), it may be a replica. Note that Mugen have not sold the badge in the colored red-gold-black diplay bag, only the more generic bag.
2. Painted versus embossed. The genuine badge is embossed on sturdy metal. If you run your finger over it, you should be able to feel the logo.
3. Logo spacing. The replica badge has extra spacing around the kanji and MUGEN logo. The genuine has an overall tighter design with less space around the kanji and MUGEN logo.
Here is a comparison photo of the packaging.
Photos of genuine badge courtesy of Wilhelm C.
You can find genuine Mugen emblems and decals on the King Motorsports online store:
http://www.kingmotorsports.com/c-147-decals-stickers-emblems.aspx