Hi,
Wow, that's a big boat!
What is your ball weight?
The prob is, even just a litte payload in the car and you will be over your GCM and therefore illegal. And you know what insurance companies are like! Even your spare and just some toolboxes in the rear will tip you over.
We went to a public weigh in at the Brisbane Showgrounds a few months ago. You'd be surprised just how heavy the Jeep is with just a bit of stuff in it! But if you can travel light, good luck to ya! They weighed each axle as well as total GCM, van on it's own and car on it's own. Well worth attending.
The Jeep tows so well, I'm not surprised that it tows your 3.5 tonne boat with ease though.
Enjoy!
Cheers,
Sally