Down At The Car Wash

at my office the parking lot is lined with trees. trees that are evidently sapping right now. last night when i left the office my car was covered in sap. i tried to clean the windshield off with my washer fluid, but to no avail. so i decided to hit the $3 carwash on my way home. i pulled up to the drive-thru carwash and inserted two $1 bills. next i proceeded to insert 4 quarters to pay for the remaining dollar i owned. to my surprise, there was no coin slot! i go to this carwash all of the time, but i normally use there debit card feature, or i'll get the $5 job and use a $5 bill. i never noticed before that there was no coin slot on the freakin' machine!? i tried to get my money back by pressing the cancel button and the change button, but all that did is make the machine beep. i decided to drive the 1/3 mile to the gas station and exchange my quarters for a dollar. since it was 9:45 at night i thought my odds were pretty good that no one else would pull up to the car wash and capitalize on my previous contribution. so i race to the gas station, get my dollar, and race back to the carwash. eureka! the goofy machine stills says insert $1! i inserted my dollar, got my car washed, and all was well. but, i just have to pose one question. what kind of self serve car wash doesn't accept coins?