[wimorrison]

you don't need to go to the expense or complexity of VIDA

I use an ELM 327 (wifi version) with OBD Auto Doctor on my iPhone and I get all the details that are needed. If you have Android then get the ELM327 (Bluetooth version) and use the free Torque app.

They will enable you to see how quickly the engine is heating up and that will tell you if the thermostat is knackered - which I doubt as they very rarely fail, and highly unlikely in a new car.

Remember that the way the aircon works is to fist COOL the air and then heat it. This dries the air and stops you getting the misted windows - if you switch off the aircon then that stops the cooling aspect, but can result in badly misted windows