There is a piece of yellow paper that came attached to the back of mine. I just looked at it and it says 4" behind as well. The space it says it wants for cooling is one of the reasons I opted for a stand that it sits on instead of an enclosure.
The A2000 does have the fans as well.
I really like the TV, but wanted to give you a heads up on that aspect of it. I would normally recommend it (actually had my dad get the 55" A2020 a couple of months back), but if you are concerned about that aspect it may not be a good fit. You could try to call Sony and see what they have to say about it before you order anything.
I'd have to dig out the manual for the A2000 to see if it was mentioned there as well.
If you see an A3000 on display somewhere, especially a Sony Style store, it may still have the piece of paper attached to the back, assuming the A3000 has one.
