During our latest deluge of rain I was reminded of how much I liked watching roadrace cars in the rain. It made the experience of being wet and cold so much more enjoyable. The rain would highlight what is going on around wheelwells and at the rear behind spoilers and the like.
The same goes for Rally cars on a very dry gravel back road (Think El mirage)
You can even turn long boring trips down the interstate freeways into learning time, provided it is raining or even better, it is just cold enough for snow. Then the slush builds up on the side of the car and around the wheelwell openings. When you stop for a restroom brake look at the record of airflow in these areas.