the 360 has a rotating cuff... rotated with the small cup facing up it is a gravity feed airbrush and can get some amount of small detail, rotated down you can stick a bottle onto it for large jobs that will require a lot of paint.
The ability to have a large amount of pain in the bottle comes at the expense of having to raise the pressure to pull the paint up into the airbrush. The ability to shoot with the cup in the up position comes at the expense of having to refill the pain cup often.
Both are good brushes I have heard (I don't own either although I own the sister brush to the 360, the Badger 155 which lacks the rotating cuff, mine is always siphon fed). To me if you spray cars you will be using the same color for a longer amount of time than you would be shooting details onto it. Something like the Omni4000 or Badger 100LG would both allow you to carry a decent amount of paint in the cup, while at the same time being able to shoot at lower pressures and if need be go in close to the body for a small piece.
Maybe you should read this article by a member here:
http://www.craigcentral.com/models/ab.asp
It answers a lot of questions like do I need a gravity fed or a siphon fed etc... Good luck to you!!