We do a flush every other time we change the oil (just to keep it clean as well as we can, probably over kill but we'd rather do more than less!) We bought the van used (with 54k miles) and most likely all is fine. No issues but I'd like to just check the level if possible. I took my van (2017 Toyota Sienna) to the local Toyota dealership for a fluid check. When I got there the nice guy said he'd check it for me... just pop my hood. So I let him know my transmission is a sealed transmission and popping the hood would do nothing lol. Then he said "OH, you'd have to talk to the mechanic and I have no clue how long that would take, I dont even know how they would check it" Which he wasnt the mechanic so him not knowing didnt worry me, but its definitely not a regular thing they do so I just left! 

So if you could do a video on check it, that would be wonderful (I'll be In Tennessee in two weeks if you need a van to do it on 😉 LOL)