Noooo never worked for them at all
But as a designer and engineer i can appreciate the car and what it took to get it into production, and what Richard & the TTech staff did to keep it going for so long, still be top-end competitive and with minimal resources and staff with what was pretty much a unchanged design. No mean feat to do that i can tell you. Team Xtreme also deserve praise for the evolution design of the X11, a car that is still competitive today on selective tracks.
I've spent years learning about them, buying dozens of them, racing & modifying them with new parts. I dont know everything about them by a long shot, but probably more than most.