His "weapons" are batteries, one turns into a shoulder-mounted launcher and the other turns into a pistol. Since they are batteries, yes, they go in the back. Good find on that one, Soundwave was always one of my favorites, and I only recently learned that there were MORE cassettes with other designs that are fairly rare... and that just made me want 'em all even more!
I couldn't get over the colors of G2 or the hollow feel some of them had, it made 'em seem cheap. I do like the designs of the auto-changing Machine Wars vehicles, Hoist/Hubcap (reused in RID and now here in RM) in particular is the best example of a real transformation of any auto-changer I know, things really look neat as panels move, parts change orientation, and the head reveals. But I'm not as much a fan of the jets simply because I hate Transformer jets that are from the school of design where alt mode is "jet on top and robot arms & legs are a large bulky attachment hanging on the bottom" like Armada & Energon Starscream, Armada Thrust is the only recent TF jet I can think of that avoids this.