I have the need to install a child seat. He is 4 years old and to big for a harness. I can use a booster seat upfront to comply with the law because it has a shoulder belt. The rear seats in my 84 bird do not have shoulder belts and I can not find a car seat that uses a harness above 40 pounds.
Does the 86+ birds have shoulder belts for the backseat?
http://www.diapers.com/p/evenflo-booster-car-seat-crawford-1035695?view=info&sku=EV-479&qty=1
This seat is good for up to 100 pounds. Mount in the backseat center with a lap belt. Run the anchor/tether into the trunk. Should be easy to guide into the trunk area, and you are done. Thunderbird/cougar 83-88 never had rear shoulder restraints, and even Mark VII did not get them until 1990. This should be a safe install for you, i had the same issue with a 70 Torino Convertible a few years back.
I remember being buckled into a car seat in the back of my parent's '87 Plymouth Voyager. It just had lap belts. My we've come a long way in car seat design.
I remember sitting on my dad's lap steering the car on the highway, LOL
When I was a kid (a very long time ago) I used to stand in the back seat area straddling the hump and dad's 65 Galaxie 500 had a metal dash! When you came home from the hospital as a new born, your mom held you in her arms.
Car seats, "WE DON'T NEED NO STINKIN' CAR SEATS!"
my vert only has lap belts in the front
Just to note I was making my comment because of how unsafe we all were in cars as children. 20 years from now people will find how we buckle our kids into cars unsafe.
I remember our family of 6 all piling into Dad's regular cab truck when I was little. Unless of course it was a nice warm day, then us kids could ride in the bed. I would never do that with my kids, but back then it was the norm!
In Utah its legal to ride in a truck bed, as long as all available seat belts are used.
If i ever get around to stripping my interior, I've had thoughts of installing car seat anchors. When i only have one of my two boys with me, ill let them sit up front. I did get pulled over once with my kid upfront. The cop asked why he wasn't in back. I told him the booster seat says to use with a shoulder belt and the back only had lap belts. No ticket was issued.
I also went to a car seat safety day that the Utah highway patrol does a few times a year. They said the back seat is still safer even if it is only lap belts.
The problem is when the kids are older and using only a booster, lap belts are not safe for use with them. Thats why i suggested the larger "car seat" option up to 100 pounds. The lap belt secures the base, and you slip the anchor/tether into the trunk area and just tie it off very tight to the rear support bracing and its secure as hell. This was the same thing i did for a few years when i had the Torino Convertible with my son.
I seem to recall in one of my mid80's fox brochures and illustrative / picture of "optional" child restraint system for the back seat ,,, I think....


These were from the 1983 Thunderbird brochure. These were for front seat only with the shoulder restraints.