AFAIK this Microbric "Viper" robot is discontinued, but I just saw this video and liked the stop motion animation showing the modularity and reconfigurability. xanadu has made some great stop-motion assembly videos of an Activity Bot IIRC.
: It's also amazing how adding shiny mag wheels and a few curved decorative pieces (spoiler & wings) really jazzes up the look of what's essentially just another boxy robot chassis. Based on my experience in the toy biz, you could bank some serious coin selling customization kits for Scribbler & Activity Bot with nothing but plastic pieces & labels. I'd suggest molding them yourself. If you don't want to do that, at least host the 3D files on your site and let people 3D print them. Kids could do Battlebots with jousting lances and armor that "blows off". Just another way to engage kids, sure can't hurt. I have lots of professional artist friends who could do some sketching & visual exploration if you like.
For some reason, I see a custom S3 done as a lowrider with a flame job, doing a hydraulic wheelie bounce and playing "La Cucaracha". Next Parallax Expo/party, please have a customized robot show or contest.
"When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."
- Pablo Picasso