For all weather mats (which are an absolute must-have for the harsh winters we have here in California
) if you search here on the forum, folks go with Hexomat, Lloyd, Husky, or Weathertech. I personally went with Husky mats up front and in the cargo area (had to cut a few areas as instructed so that the 3rd row seat could fold down) and Lloyd for the 2nd/3rd row, which allow the seats to slide back and forth since they don't cover up the tracks. Some of the mats from the other manufacturers (including the ones from Toyota) cover the tracks, so they limit the amount the seats are able to slide - not sure if that's a big deal to you, but something to keep in mind while you're researching.
As for dashcams, I've had a Blackvue DR500GW-HD installed in my GS for over 3 years, which I've been happy with, so for my Sienna, I went with another Blackvue. This time I went with the DR-650S-2CH, which has both a front and rear facing camera. I have yet to install it bc I was waiting to get my windshield replaced under warranty, which I had taken care of last week.
I ordered the Citycruiser V3 window visors from Vankulture.com (https://www.vankulture.com/product-p...uiser-v3-visor
) which just arrived today, so I still need to install them as well. I'll let you know how that goes.
Not sure if you have any kids (I have one on the way - literally due any day now) but I've been looking into seat covers to protect the seats. I initially bought a set of generic neoprene covers from Costco but really wasn't happy with how they fit, so I returned them. Covercraft makes vehicle-specific covers, but they sure are pricey - about $200 per row. I might just go with a set for the middle row since that's where the car seat is installed...
Finally, one major gripe I've read about here from fellow SE owners (outside of HID headlights and memory seats) is the lack of power rear quarter window vents - there is a post here from some guys who were able to retrofit the motor and switches from XLE/Limited models. I've bought all the parts (afaik
) but again, have yet to install them - apparently there's a difference in wiring between the '11-'14 and the '15-'17 models that makes it a little bit more involved on the newer models, but still possible. Not sure if your a big DIYer, but you might want to look into that as well...
Lots of stuff to keep busy with the van - hope the kid will spare me some time to get to all of it once I start paternity leave in a few days