Plan on the vehicle becoming a rust bucket real quick. Rinse as soon as you can, check the brake lines now and be sure there is no rust or corrosion on them. They have a tendency to blow out at just the right time. A 05 vehicle will be showing rust from road salt already. I think the frame on that vehicle may be tubular - If so check the areas over the wheels and under the passenger compartment for early rust. If the under carridge is nice and clean, it might be wise to buy a #^&#^&#^&#^&load of undercoat paint in spray bombs and coat all surfaces with it. The road salt does plenty of damage on it's own. Salty sand will do a number on the interior also. Try and vac it clean often. This is a problem when jumping in with wet waders. Keep off wet sand and standing water. You might find yourself digging out.
For further information go to the
MBBA | Massachusetts Beach Buggy Association | Leave Nothing Behind But Our Footprints web site and you will get lots of info there. If you see a vehicle with the MBBA sticker, stop and talk to the owner. You will get plenty of info from them.