Hi all , I've noticed that I think I have the problem of the temperature gauge goi g to 70 then going to 90 when sat in traffic then back down to 70 when moving , firstly. Where do I get the the thermostat at a good price ? I'm assuming it's the main thermostat 2nd. Would that also stop the heater In the car from getting hot ? It gets warm but not hot any help would be appreciated thanks