Not sure if alpine is working?

About a month ago, I left two cups in my the cup holder in my car with some water for a few days. One morning while driving to work, I noticed a small presumably German roach in one of the cups. I removed it and inspected the other cup and found two more dead roaches in the other cup. A week later while I was driving I saw another roach crawl out from the roof of the car onto the windshield. A week after that, I found a baby one on one of the seats. Safe to assume there is some sort of infestation happening. I purchased alpine wsg and mixed 1/2 gallon of water with 10 g alpine. I sprayed under the seats, carpet, trunk, door sills, gap between roof and windshield, I used about half a liter. I expected to see a bunch of dead roaches today, but I didn’t see any. Would this indicate that alpine did not work?