A vision system for a vehicle, said vision system comprising: a camera 11 having a lens 20 and an imager 16; wherein the lens 20 is positioned to capture a view exterior a vehicle, and wherein, with the camera 11 installed at the vehicle, the view of the camera 11 includes a portion of the vehicle; wherein the imager 16 is configured to receive images from the lens 20; a camera microcontroller 18 operable to control the application of an overlay 26 to the images 25; an in-vehicle display 24 operable to display images captured by the imager 16; and the camera microcontroller 18 is operable to receive data from the imager 16 and the camera microcontroller 18 is operable to detect a reference point 34 in the images using the data and, responsive to a determination of an offset of the detected reference point 34 relative to an expected location of the reference point 34, the camera microcontroller 18 is operable to determine an offset amount with which to shift the overlay on the images 25; and characterized by: wherein said camera microcontroller 18 is operable to detect reference points during reference point detection cycles and wherein said reference point detection cycles are triggered at least one of (i) while the vehicle is driving forward, (ii) while the in-vehicle display is not displaying camera images, (iii) while the vehicle is driving at least 40 km/hour, (iv) while the vehicle's steering angle is within a selected amount of degrees from zero, (v) while the outside temperature is within a selected range, (vi) while the vehicle headlights are off, (vii) while a heading direction of the vehicle is within a selected range, (viii) after a windshield wiper of the vehicle has been off for a selected period of time, (ix) while the time of day is within a selected range, (x) after an amount of time that the vehicle has been driven without stopping exceeds a selected amount of time, (xi) while a determination of an offset amount has not taken place already on the current day and (xii) after a selected period of time has elapsed since the previous determination of an offset amount; and responsive to the determined offset, said camera microcontroller 18 shifts the overlay 26 applied to the displayed images. a camera 11 having a lens 20 and an imager 16; wherein the lens 20 is positioned to capture a view exterior a vehicle, and wherein, with the camera 11 installed at the vehicle, the view of the camera 11 includes a portion of the vehicle; wherein the imager 16 is configured to receive images from the lens 20; a camera microcontroller 18 operable to control the application of an overlay 26 to the images 25; an in-vehicle display 24 operable to display images captured by the imager 16; and the camera microcontroller 18 is operable to receive data from the imager 16 and the camera microcontroller 18 is operable to detect a reference point 34 in the images using the data and, responsive to a determination of an offset of the detected reference point 34 relative to an expected location of the reference point 34, the camera microcontroller 18 is operable to determine an offset amount with which to shift the overlay on the images 25; and characterized by: wherein said camera microcontroller 18 is operable to detect reference points during reference point detection cycles and wherein said reference point detection cycles are triggered at least one of (i) while the vehicle is driving forward, (ii) while the in-vehicle display is not displaying camera images, (iii) while the vehicle is driving at least 40 km/hour, (iv) while the vehicle's steering angle is within a selected amount of degrees from zero, (v) while the outside temperature is within a selected range, (vi) while the vehicle headlights are off, (vii) while a heading direction of the vehicle is within a selected range, (viii) after a windshield wiper of the vehicle has been off for a selected period of time, (ix) while the time of day is within a selected range, (x) after an amount of time that the vehicle has been driven without stopping exceeds a selected amount of time, (xi) while a determination of an offset amount has not taken place already on the current day and (xii) after a selected period of time has elapsed since the previous determination of an offset amount; and responsive to the determined offset, said camera microcontroller 18 shifts the overlay 26 applied to the displayed images. wherein said camera microcontroller 18 is operable to detect reference points during reference point detection cycles and wherein said reference point detection cycles are triggered at least one of (i) while the vehicle is driving forward, (ii) while the in-vehicle display is not displaying camera images, (iii) while the vehicle is driving at least 40 km/hour, (iv) while the vehicle's steering angle is within a selected amount of degrees from zero, (v) while the outside temperature is within a selected range, (vi) while the vehicle headlights are off, (vii) while a heading direction of the vehicle is within a selected range, (viii) after a windshield wiper of the vehicle has been off for a selected period of time, (ix) while the time of day is within a selected range, (x) after an amount of time that the vehicle has been driven without stopping exceeds a selected amount of time, (xi) while a determination of an offset amount has not taken place already on the current day and (xii) after a selected period of time has elapsed since the previous determination of an offset amount; and responsive to the determined offset, said camera microcontroller 18 shifts the overlay 26 applied to the displayed images.