The baby seats are bucks 200 or a little less, You also should ride back there some and get an idea of the bucking the back seat does! No whoops or bumps with kids in the back seat, as the back seat launches you in the air or trys to.
They make those donuts of memory foam for the little necks, they are used for adults sleeping on planes.
My kids have been riding with me since they were babies. But I rarely ask them to sit in a back seat anymore, back seats in these things are just not a comfortable ride to much bucking going on.