That said, please, please follow these easy instructions and apply a mount appropriate to do so now, or come by our paddock after you get the transponder for help:
less that 12" from the ground unobstructed
Protected from impact damage
SECURELY mounted in case of an off road excursion
No idea what car you have but a commonly good location is the rear of the spare tire well. You drill 4 holes in the sheet metal for two ziptie locations after you get the transponder. Then you use at least 6 high quality zipties to attach it...two through each mount the way you would think, two diagonally, two more holding the transponder onto its own mounting plate. Is this overkill...no. Replacing it is over $300.
FYI, we will be close to the timing tower, on the track side with the black 1995 Camero sporting weird stuff sticking out of the hood. Red Ford F250 and generic white enclosed trailer. Seriously, come by. Too many newbie teams get this wrong when it is so easy to get right.