no issues with signal on my v1 mounted in the same spot. it is probably because (like said earlier) you have it facing the sky.
2007 335i E92:
JZW Tune | Alpina B3 Flash | Orion V2.5 | Black Kidney/Mesh Grills/Window Trim | CSL Spoiler | V1| 6000K HID Headlights/Fogs | Painted Reflectors | Hamann Roof Spoiler | BMS Intake | M2 Catback Exhaust | Hamann Lip (destroyed by driveway
Coming Soon: Lowering Perches, New Hamann Lip?