Kelney is right - you *definitely* need the Temporary Import Permit and on the water liability insurance. If you plan on taking Mex 2 down from Sonoyta to Santa Ana, I don't think there is an Aduana stop (it's at 21km just south of Nogales), so you'll only need it for the marinas. Figure on roughly a 6-7 hour drive. I can make it from Phoenix in 7 hours not towing, but it take 9 hours towing.