It's not mod, but I've been on the podium consistently in USVTA with my TC5. The relatively stiff chassis plate and top deck seems to be well suited to the new CRC carpet and USVTA tires. I'm right there with the Awesomatix, Xray, newer TC6/7's, etc.
It's taken me about a year to dial in a good USVTA setup on the TC5, but it's working really well for me.
Mark