The E46 OAT sensor is definitely located in a vulnerable place.Let me guess....you found the OAT sensor dangling by a wire under the driver`s side A-frame ?
On my E90, they solved this problem by putting the OAT sensor much higher and in the center behind the front bumper. So is this better? Absolutely not! My OAT sensor failed, and I had to remove the entire front bumper cover to get access and replace that sensor.