Our youngest, who just got her license, was gifted her late grandmother's '04 Vue AWD/CVT...and I remember reading multiple threads about what a nightmare these are. 
The "good" news is it's been garaged it's whole life and only has 40kmi on it.
Her grandfather had her ask me to change the transmission fluid on it. I know that's a touchy subject for some, but does anyone have specific experience with the AWD/CVT setup in these, and whether changing the fluid at 40 is a good idea?
Unfortunately, due to the connection to her family with the Vue flipping it and buying something reliable is not an option.
At 40k I would definitely do it. It is older transmissions that can not like new fluid.
I have specific experience with Honda's CVT, not GM's, but my recommendation is change the fluid and change it often. I change mine at 24k mile intervals, sometimes more frequently, and the difference in how it feels is very noticeable.
God Bless Ya?
I have a Vue and have written extensively about it but mine is a 5pd manual.
All I know about the CVT is that it is a nightmare. I have never researched what it takes to maintain them. The typical reputation is that it might make it 60-80k miles. When it goes, there is no real fix. Replacement units will be JY units and they will likely already have 60-80k miles on them too.
Good luck
Just to be sure, you have the 4cyl w/auto?
If you have the V6, it is not a CVT, it is a 5 speed auto.
it was free. maintain it and let her drive the wheels off or transmission out from under it, whichever comes first? it'll be the transmission.
History:
'02-'04: The 4 cyl auto is a CVT in both fwd and awd versions.
'05: Mid year, fwd 4cyl switched to a reliable 4 speed auto. The '05 awd remained cvt
'06-'07: no 4cyl awd was offered and all 4cyl were fwd with reliable 4 speed auto.
Swaps from cvt to 4 speed auto can be done but it seems to be rather extensive including the need for the 4 speeds ECU, Body Control Module, etc so that it can read the new trans. Seems this swap is best done if you have the whole donor vehicle. Swaps from cvt to manual have been done also.
Many have speculated that one of the reasons GM killed Saturn was to get out from under this whole cvt debacle. Likely not true but adds emphasis to the size of the issue. I believe there was a class action lawsuit that never settled. The same cvt engine combo was used in the '03-'04 Saturn Ion too which also went to the same 4 speed auto in '05.
You do have a few things going for you.
1. Free!
2. Young drivers don't put on that many miles per year. At less than 10k per year, you could get another 3-4 years before getting into the danger mileage range.
3. Due to dead cvt's, JYs are full of low mileage, no damage Vues so replacement parts are plentiful.
4. Plastic body panels are durable and plentiful in JYs if not durable enough.
5. The Vues have really good crash ratings to protect the princess.
My Vue w/o cvt has been cheap to keep on the road and now has near 250k miles.
Points to note:
They go through rear hub bearings. It is an easy repair. Some say Timken Brand only but I chose the version w/ a lifetime guarantee and I have had to exerciser that guarantee.
Pro tip: it is the same bearing for the left side and the right side. As an example, if you bought a new right side and then the left failed, your reciept from the right side could get you a replacement for the left side. So I hear...
Front axle half shafts are known for being a real bitch, especially in rusty climates. I gladly paid to have someone else take car of these.
They go through front sway bar links in about 40k miles. This will be known because you will get "creaking and squeaking" from the front end.
Buy Lifetime. The part is like $20. Taking off the front tire is the hardest part of the job.
Retinking:
I recommend lifetime parts but you are not going to see 100k miles so maybe rethink that part. 
I have to agree with everyone else. My buddies 5spd has been awesome, but nothing but horror stories about that CVT. Aside from a weekend changing wheel bearings and rear shocks, it's been dependable, and almost fun to own.
In reply to JohnRW1621:
It's definitely a 4-cyl, and I remember when my (now ex) in-laws bought it new in '04 that it had the CVT. I shuddered thinking about it then, and that was long before they had the long history of problems they do today.
You may have the last functional VTi transmission. Congrats!
Never shift from drive to reverse while moving. Never from reverse to drive while moving. Do not neutral drop, at all, ever, even 100 extra rpm. The AWD ones lasted a little long(minutes, maybe) because they less rarely dealt with the stress of wheelspin followed by suddenly gaining traction. By subjecting one to any of these circumstances, I could break a brand new VUE right on the lot with 10 miles on the odometer.
When it inevitably frags itself,
Swap to a stick shift. The rest of the vehicle is pretty decent and very functional.
How's the timing chain noise?
My wifes had an 04 ion with the 2.2 since 06. Its at 140k on the original transmission. Its a 5speed auto, ive never cared enough too learn anymore about it. Hers occasionally acts strange cold but id drive it anywere.
In reply to belteshazzar:
I've not listened to it yet, though my daughter said it the car is noisier than what she's used to. We're going to take it for a drive tonight so I can hear what's going on.
We took it for a long drive tonight & I noticed the trans sounds a bit like a whirring electric motor during accelerate/deceleration. Is that normal for the CVT, or is the end near?
petegossett wrote:
We took it for a long drive tonight & I noticed the trans sounds a bit like a whirring electric motor during accelerate/deceleration. Is that normal for the CVT, or is the end near?
my wifes ion only makes that sound when cold. usually goes away after it shifts into second the first time each morning.
In reply to dropstep:
We drove it 50 miles, each way, to dinner & back. It did it at every stop, though worse when cold.
Oh, and it actually has 85kmi, not 40 like I was told originally.
One "good" thing though - my daughter's heels don't reach the floor when she's driving, so there's at least a legitimate reason to get her something else. I'll let her spend some time with it though & see what she thinks.
