My outside air temperature is giving a wrong reading, showing 10 degrees today when clearly it was 18+ t-shirt weather, where is the sensor located and is it easy to change if faulty, and price if anybody knows. If of course this is the problem.

The sensor is in front of radiator, open bonnet and look down at radiator, it is clipped to airco pipe I think.

Normally, it would read this low if broken or if it is in water (eg if unclipped and lying at the bumper).

Could also be water ingress into the sensor plug.

They die easy on all cars, just get a new sensor and it should rectify it, hth.