[Jakerooni]

The air compressor will save you the most time over all the other stuff. I would almost say that every detailer out there should have some sort of way of blowing out all the seat tracks crooks and crannies. (air compressor being the easiest way to do this) The PW will save you quite a bit of time as well. The LGM isn't really going to save you anytime but it might net you some better results. A good assortment of scrub brushes will save buttloads of time as well. But getting the process down and just knowing how to tackle things before hand is the biggest difference to all detailing when it comes to saving time. Like Todd said wasting time walking around looking for stuff is a huge time waster another is not knowing your chemicals and products and what they can do. Trying this out and that out only to find out they aren't working then looking for something else that does will eat up time like no other.