The point of cleaning your car in the bigger picture isn't so that it's clean for x number of days. Its the fact that your keeping the clearcote and the paint in clean and free of any chemicals that can harm and deteriate the condition and quality of the paint.
In fact I'm day ( yes day ) 2 out of 3 of detaling my new vRS, and doing the whole process from start too finish, if I had five days I would use five days.
When I wash the car every 2-3 days, the car is in superb condition underneath, and the whole process makes cleaning and drying very easy.