Thanx, i thought it was a cool idea and wanted to share it with my T3 brothers and sisters.
without sounding like i'm advertising.....visit teamirsrc.com and their transponder/servo mount is listed under TC3 upgrades. part number is irs148 and retails for 27.50. and its blue.
i do not know the hardcore part number off hand but their website is racinghardcore.com. and theirs come in different colors. about the same price.
otherguy - most people/tracks would like the transponder to be within the chassis (between the front and rear wheels) or in the bottom right of the windshield. ask some of the locals at the track(s) you race at and i'm sure they'll be more than helpful. good luck.