I was a Pump Jockey while I was in high school, worked for SOHIO. At the time regular was 37.9 cents per gallon and a 5 dollar fillup was 13.2 gallons. Premium was 41.9 cents per gallon and a 5 dollar fillup was 11.9 gallons. By policy Sohio mandated that every customer got their windshield, rear window, and drivers rear view mirror cleaned with EVERY purchase. They had Secret Shoppers who did nothing but check up on the service at the company owned stations. At that time you could easily get all the glass done well before the pump hit 5 dollars if you were filling with regular. If you were pumping premium you could beat that 5 dollar cutoff but did need to do some jogging and didn't have the time to do any bug scrubbing. At a guess I would say that total time to service the glass was roughly 1 1/2 minutes, or 90 seconds. So, time yourself on putting 13 gallons in your vehicle. I would bet it will take 4-5 minutes or more.