A vehicular forward viewing image capture system includes an accessory module configured for attachment at an in-cabin side of a windshield of a vehicle, whereby the imaging sensor views through the windshield forward of the equipped vehicle. With the accessory module attached at the in-cabin side of the windshield, and while the vehicle is traveling along a road, a control processes captured image data to determine (i) presence of an object of interest viewed by the imaging sensor and (ii) location and/or movement of the object of interest viewed by the imaging sensor. The control, responsive to the processing of captured image data and responsive to vehicle data received via a vehicle communication bus, at least in part provides at least one selected from the group consisting of (a) traffic sign recognition, (b) traffic light status detection, (c) adaptive cruise control and (d) pedestrian detection.