Hobie's published weight figures should now be pretty accurate (they weren't for years) so going on their fully rigged weight you would only lose the paddle, miragedrive, seat and aka's from that figure of 84kg.
Remember that the big difference between '15/16 AI's and your '14 are a larger hull, much longer and heavier ama and a built in/non removable centreboard.
The most I'd say you could save in weight by carrying the items mentioned inside the vehicle would be around 12kg, so a rooftop weight of 72kg or so should be realistic.
See here for weight info discussion:
http://www.hobiecat.com.au/forums/viewt ... 71&t=53756