Distance between iso-fix anchors

The second row seats in the Prius v sold in North America are very different than those in the Prius+ and Prius v sold elsewhere.

For accuracy, get your measurements from a European Prius+.

 

If available download the online version of the Owner’s Manual of the model and year in question. Sometimes the design restricts which positions in the rear are recommended for car seats. If the answer is not clear I would contact Toyota directly with this question. I know the Britax Baby Safe Car Seat I had in the past had fixed spacing between the latches, and the picture posted does not look like you could fit more than two, in the outer seating positions.

BUT, in my research of the past, if your child seats offer the option to use the seat belt, the seat belt can handle far more weight than the ISO-fix, so then I would just use the belts. ISO-fix was a convenience, but the belts are stronger! I just checked ours and as Offline noted, I do believe the seats are different. The latch points are hidden behind a zippered cover. I think this is a no-no in Europe. Also, I measured about 11 inches between the latch points on the two outer seats. In between the latches across the middle seat is far wider. I also do believe that the latches only allow (technically for safety) one attachment, so that in our case only two ISO seats in the outer positions as well.

 

I've put 3 child seats in the back (on a 2010 Prius), all connecting to those strong points. It's technically possible, but now that I think about it, and engineer might frown on it, the central seat is doubling the load on the inner strong points, and connecting on a more diagonal angle.

 

Do check the weight limits on those ISO attachments. They aren’t/weren’t very strong. Could have been changes since my son was small. He is now twelve and weighs practically the same as me. He grew out of the limits really quick, including the seat weight that is. I do believe it is only one seat per set of latches. Some seats were fixed in width as well, like the Baby Safe. You could not latch it on the wider center even if you wanted to.

 

57 cm.
I have three kids (5,7, and 9), so I can tell from experience If we travel as whole family, then all the kids are on the second row. One seat is with hard isofix anchors, middle one is without, and the third is with kind of belt-anchros to isofix.
The first seat is Römer Kidfix -seat, the other models I do not remember by heart.

Isofix anchor points are hard to reach, as they are hidden inside the seat padding. In our old car (Citroen C4 Picasso) isofix mounting was just a mater of click, but with Prius+ you have to practice and even then it is a process

You'll also need to think how you reach the seat belt buckets. I have there short rigid extensions.

Here are the pictures:

 

Just be careful with having the ISOFIX seat in too long. The zipper that reveals the ISOFIX mounting has a slight tear in the vinyl/fake leather seat.