Measure ambient temps outside the car and measure the temp in the air filter. If it works I personally dont care what it looks like.

" looks " and function usually cost too much. So it depends on your budget.

I like Dougs test, thats the sorta test I would have done

back in the day I had a problem with my starter getting killed by my exhaust. We got hold of a pipe wrap that is used when welding. It was about 1 inch thick and SERIOUS stuff. You could put the wrap on your hand and put a piece of glowing red hot metal on your hand and have no idea.

Overkill but it worked

RW