Safest position for toddler car seat? Is center ok to use other latch?

The manual specifies using only the two outer seat positions for LATCH.

This exploded diagram shows the LATCH anchor bars, which are two separate pieces, parts 73705 and 73706:
Prius Rear Seat Plastic Latch Cover | PriusChat

If a child seat is put in the middle, it would be connected to the inner end of each of the two anchor bars, which may result in an insecure or unsafe fitting.

 

I have 2 kids now, so not much choice, but when we only had one, the seat was in the middle. For my old car, this meant mounting using the seatbelt. Neither LATCH nor seatbelt mount are inherently safer(LATCH obviously being more convenient), but putting the seat in the middle is definitely keeping it farther from any points of impact.

 

If you read the seats' instructions further you'll find a trend to switch to belt above a certain weight. I think the belt is safer....

SCH-R530M ?

 

My car seat has a latch on the back that I latch into the top seat while using with the seat belt in the middle. The seat feels much more secure.

 

I have had 3 car seats in the back many times. I keep my youngest in the center using the LATCH system. The other seats are just booster seats so I use the seat belts for them. I don't feel comfortable enough putting my toddler car seat in any other place but the middle. I did read in the manual that it is not recommended by Toyota to use the center seat with the LATCH system. To be clear for yaz the LATCH anchors in the back of the seats can be used regardless if using the LATCH system or seat belts.

 

I suspect that's probably the case. You could call corporate and see it they'll commit themselves:
Toyota Customer Experience Center: 1-800-331-4331

 

In another thread there's a photo of the Plug-in back seat with everything removed so that the LATCH rails are clearly visible. I would think that the rails are the same on other models.

In the photo you can see that each end of the LATCH rail has a single fixing bolt directly behind the attachment point, so in theory the load on each bolt should be the same no matter where the child seat is affixed.

 

You can't use the lower LATCH anchors to install a car seat in the center position in the Prius (or in most cars, actually--only a few manufacturers allow "borrowing" the LATCH anchors to install with LATCH in the center, and almost none give you six anchor points like Acura does). You can install in the center using the seat belt, though, which is pretty easy (that's what we've always done) and just as safe. (In fact, you must use the seat belt anyway once your child is about 40 p0unds, because LATCH anchors are not approved to hold a weight of more than 65 pounds--car seat plus child.) Toyota is not ambiguous about this--it's explicitly forbidden (and most other car manufacturers have the same policy). Not worth messing around with, IMO, because technically speaking, a seat installed in the center with LATCH is not legal and not covered by your insurance should anything happen. But it really is easy to learn the seat belt install, I promise!