Much as I love Bumblebee, I've always felt (even before Dreamwave) that Goldbug was sort of the 'upgrade' version, and that getting rebuilt later as Bumblebee was a bit of a backward step. So I kind of felt obliged to re-upgrade my Bee into Goldbug.
Simple case, really, of repainting the outer hull of the car a golden yellow, followed by a metallic glaze. I also reworked his head by resculpting his face and jowls, and using hot glue to fabricate light piping and a new visor.
With G1 Goldbug...
New face close-up
The lightpiping's not quite as effective as Hardshell's, but it still works...
Goldbug and Hardshell: best of enemies...
And vehicle mode. I think I'll be leaving off the spoiler for Goldbug to increase the difference between the two. I'm in two minds, though, whether to fill in the gaps or to leave the spoiler as an optional add-on.