Well Iam getting close to haing 20k on my 06 sedan and have been looking at getting flushed soon. I was thinking of going with Amsoil full syn transmission fuild. Do you all think this would be good?? Also they say you can go for 50k miles or 5 years before the next flush. What do you all recommend

If you still have warranty you need to stay with OE Nissan fluid or it will be voided.
The general consensus is the the Nissan fluid is a high quality synth so why change.

go flush it with the OEM Nissan fluid just for the sake of your warranty.

I mean, it shouldn't make much of a difference for the car. from what i've heard, its basically just regular tranny fluid with some lubeguard red. you should be fine running amsoil.

Use Nissan Matic J only. If something were to happen to the transmission, they could deny replacement because of the wrong fluid. And you can probably go another 10K before you need a flush, and replace differential fluid then too, its up to you.

I would heed InTgr8r's advice while under warranty, then you can think about switching to Amsoil.

If the fluid color is the same, I wonder how the dealer would actually be able to determine it was non J-matic.

They would probably ask for service records to verify it was taken care of correctly. THEN they would know which fluid you put in. That would give them an out. Not necessarily because the Amsoil is any better/worse than the J-Matic.

I know the Amsoil fluid is 100% compatible and probably a better product than the OEM fluid.

I would stick with OEM fluid.

Yeah but when regarding warranty, compatible and OEM are not the same thing.....

That's correct.
The owners manual specifically says, anything other than OE will void the warranty.

It says it somewhere on the car too, I don't remember exactly where it said it, maybe on one of the lids in the engine or something.

Thanks... I will use the OEM fuilds in tranny.

Once your warranty is done you could probably use whatever you wanted.