right on then why don’t you wash your car 2 to 3 times a day? 
The car wash frequency of each weekend I provided is my typical frequency. Sometimes I get it washed Saturday. Or other weekends it may end up being on Sunday. Sometimes both days. If something unusual happens and my car gets dirty, such as a bunch of birds eating red berries and pooping all over my car, then I’ll go during the week as well. Usually with work I don’t have time to go during the week.
The difference between my showering/underwear frequency vs car wash frequency is I’m pretty consistent with controlling the environment/places I go in my car. Thus, I typically only have to get it washed on weekends. I pretty much go the same places every day in my car. I also very rarely drive with windows open in an effort to prevent bees and spiders from climbing in.
The reason I shower 3x a day is because the various places I go each day and the people I interact with differ each day. If I walk into a Chinese restaurant to buy rice, I can’t control the smell that gets on my clothes. If I go to the gym, and I’m sitting on a machine, I can’t control the sweat smell that rubs off on me from the seat. If I go into a kitchen to assist, I can’t control the smell that gets stuck on me. Recent example was an Uber driver from Hell. The Uber car was an old mini van and he stopped in the middle of the street in heavy traffic to pick me up. There was no A/C, windows were up, the inside was filthy and sticky, and he smelled like a homeless man who ate curry and hadn’t showered for a month. For the 1st time in my life, I began dry heaving and asked to get out after we got off the highway after he cut off a tractor trailer and almost got us killed. I walked 30 mins to my dentist appointment instead of finishing the ride and had to throw away my sweat shirt on the street because I smelled so bad from the ride before I went into the dentist office.