So long as the bumper has no metal you can mount the antenna behind it. Radar will pass through plastic & fibreglass but not metal (including bull bars etc)
Of course laser will not penetrate the bumper, so you need to keep that in mind. The STi-R antenna also has the laser sensors built in, but the 975r radar antenna is separate to the laser detection sensors.
The STi-R is slightly better than the 975r against multanova – as shown in our videos.
