I know you all are probably going to say its overkill, but what I will be using it for is to blow water out of crevices and around trim after doing washes. Drying engine compartmentsz after an engine clean. I'll also be using it to purge the interiors. I'm sure I'll find some other uses for it as well.
I used to work at a carwash where the air pressure was weak more often than not, and I found it very frustrating trying to perform a detail with insufficient pressure. I just wanted to make sure that I picked up a high powered quality unit from the get go and not have to worry about wanting or needing something with more power down the road.