Frontier install question

I just picked up a shiny new Frontier 90 at Target for a steal (internet return) and now we are about to play musical carseats. The Biscuit is 40 inches and 40 pounds (plus tall from head to waist), so it is time.

The Scenara will be pulled out of my convertible (The Biscuit is almost at the weight limit) and used for friends visiting from out of town when appropriate (or sold).

The RA55 will be moved to the back of the convertible (behind passenger because we have rear bucket seats) from DH's Toyota Avalon, where it is FF in the center. The Biscuit probably can grow another 3 inches or so before he will size out of it.

We have The Biscuit's Radian RF in the center of the back of my Highlander, but I think we are going to turn him this weekend because he is complaining about his ability to see out the windows.

The plan right now is to put the Frontier in the back of DH's Avalon. Thing is, that Frontier is GINORMOUS and we would like to be able to fit at least one adult in the back seat with him, which will be pretty much impossible with him in the middle. Also, it looks like it is going to block DH's rear view.

Do we have to install it in the middle to maximize safety? Will it be safe to install the Frontier FF in the Avalon behind the passenger seat? Or should we try putting it in the center of the back seat in the Highlander and hope that adults will be able to fit on either side because it has a wider back seat?

TIA!!

We have DS's Frontier in the passenger side seat in my Infiniti. We have no choice, as there is no middle seat in the second row. I feel very safe with him there in the Frontier (and I'm very anal about car seat safety).

I wouldn't worry about putting him outboard. Both my kids ride outboard even though I could technically install one of the seats in the middle. They are safer when they aren't both screaming about who kicked/hit/pinched who. Similarly I wouldn't want to block the back visibility if I could avoid it.

My car has no middle seats (mazda5) and I've never worried about it.

We have our Frontier installed behind the passenger seat too.

It sounds like there is consensus, so we will give passenger side outbound a shot over the weekend.