That is fantastic! Great job.
I did the same thing with my first daughter, and seriously thought it was a great idea. My wife came home and found us in the garage all strapped in and ready to go, but she wasn't so convinced, and refused to let me take her out. Of course, my daughter was 6 months old at the time, so that might have had something to do with it. But I had the base and car-seat secured to the back deck of my Southfork rock solid. It was perfect! I should have taken a picture of it like you did.
Well done Martin!
I was not able to take it for a real run on the river as I was voted down. Still not sure how this family democracy works - 2 votes for going on the river and one against. Mom won. I think it had to do with her watching him get a little exited and end up dumping it over backwards with him strapped in (I hadn't really strapped it on at that point) or perhaps it was my discussion with him about how we would have to duck as I cast so that I would not catch the back of his head. Oh well. We did catch 100's of imaginary grass fish that day.