Non-Contact Infrared Laser Thermometer
I haven't used it on the car yet, but I did use it on a house heater's exhaust duct. You can see how much hotter the elbows get vs straight pipe and different locations. The temperature on the exhaust about doubled at the the bends. You can use this on our car for checking exhaust and intake temps (not the air in the piping itself). The thing I would use this on the car most for would be checking temps of the crossover pipe and the intake pipe above it. I remember a school testing a Regal's crossover pipes after a run on the track with a thermographic camera. They did stock, wrapped and ceramic coated crossover pipes. You can sorta do the same thing using a tool like this.
As for intakes, I'll probably make a filter box and then use the intake in the SD Hood on the Grand Prix. For the Regal with it's stock hood, I'll either use the metal tubing CAI I have or make up the PVC pipe intake to get the filter as close to the fender as I can like most have above.