I installed the Toyota Integrated Dashcam today. (No damages to any other parts, other than it sitting a little crooked and half a centimeter lower than I would have liked

). I have 5 other cheapy dashcams sitting unused. However, running a long cable around was too much work for me to do it elegantly

. I am sure someone has, or will, sell a connector to turn the OEM open connector into a Cigarette Lighter or a USB Female Adopter. I think I saw someone selling it for Tacoma in one of the videos. Anyways, I didn't see anyone mention it here for Sienna so may be not.
For novices like me, here are some tips :
1. PT949-08210 parts list contains a Foam Tape and two Cable Ties. The instructions manual doesn't say anything about what they are for. Looking around, I found the instructions manual for Venza for the same camera. It says to use the Foam tape to wrap around the connectors. i.e. snap on the camera connector to Blue one in the overhead cavity, and than wrap it in the Foam tape. For the zip ties, I just used to them tidy it up cables up there. The overhead space is very little so you don't have to, but I put them to use since they were there already.
2. Pulling down the overhead assembly needs certain amount of determination. It takes quite a bit of pull to get them out. I was sure I was going to break something in the process. Also, note that one of the trim on the outer edges of the assembly that runs by the clip is thin and fragile. Reach in well inside of the gap and find more substantial place to hold and pull it down.
3. Snapping it up back up needs a little bit of determination too. Note that the two red tabs/clips can slide a little sideways. Push them in the other way if it doesn't snap back on relatively easily in first try.