The Front Bumper

• A common location for car thermometers is for it to be placed in the front of the car. It allows the thermometer to have immediate access to outdoor conditions, while keeping it far enough away from the engine so that it does not give inaccurate readings influenced by the heat generated there.
  
  

The Rear Bumper

• Like the front bumper, the rear bumper is another common location for car thermometers. The location affords similar benefits to the front bumper, including immediate access to outdoor conditions. It is even further removed from any heat created by the engine, which means a rear bumper thermometer is even less likely to be affected by engine heat.
  
  

Side View Mirrors

• Another common location for car thermometers is on top of the side view mirrors of the car. Like the bumpers, the mirrors afford a location that is relatively free of extensive electrical or mechanical components, is outside of the car and too far away to be affected by heat created by the engine.
  
  

Underside of the Car

• Finally, another common location for a car thermometer is somewhere on the underside of the car. Underneath the car offers an isolated location for the thermometer. However, this location may not be as ideal as on the mirror or the bumper, especially in lower-sitting cars. Heat generated by the ground or exhaust system could throw off the thermometer's reading slightly.