I always had my transponder on the servo. Other guys had it on the bumper without problems, so you're good to go with any option.
My place is a real Xray workshop in the moment- we are building the T3 '12 and we are constantly doing some jobs with the M18 Pro, since it's the middle of the 1:18 indoor season. With all these things, I suddenly received another T1. When I say another T1, I basically mean a chassis and a top deck. Since I have tons of parts, I decided to build another car, and make something new and interesting with it. So, I forgot about the T3 and M18, and in one day I built a FWD Xray T1
I will try to get a Tamiya Peugeot 306 Maxi body (my favourite rally car) and I'm genuinely excited about this. Unlike my pure spec T1 Factory Kit, this new one is a mule - T1 FK chassis, gold aluminium parts (Evo 2), T1R shock towers..... So we'll call it an Xray T1