The scent is the GREEN Palmolive Ultra Strength dish soap. We discovered this accidentally while doing the dishes and realized that THIS was the scent (which, btw, is awesome for deodorizing the car after driving past chicken farms during a heat wave...GAG)!
Here's the recipe:
Clean and empty gallon jug
1 gallon water
1 tbs. dish soap
½ cup non-sudsing ammonia or vinegar
Blue food coloring
Fill the gallon container with water and mix in the dish soap, ammonia (or vinegar), and a few drops of the blue food coloring. Put the cap on the jug and gently swirl it or tip it upside down a couple times to mix the ingredients together. You can then pour the mixture into its designated spot in your car.
This homemade wiper fluid should almost all year round, but if the temperature ever drops below freezing, add isopropyl alcohol to the mixture to ensure that it won’t freeze on your windshield when you try to use it. You can always test it to see if it will freeze by leaving it outside overnight.