Was just there last weekend with my Mav. You will have a blast. No you cant sleep on the dunes, but like MIMav said, there are many campgrounds with a few miles of the dunes. I do not suggest silver hills campground, they have new owners and the bathrooms were so stinky it almost made you puke to even walk by them. I recommend staying at Silver Lake State park. If you plan on going on the weekend, be aware that they have a voucher system and you will need a voucher whether it be to get into the parking lot if you are towing a trailer, or if your Maverick is street legal you can get a dune ready voucher. The vouchers are given out the night before at 9pm, and people will line there vehicles up at 630am to assure themselves a spot. I dont think you will have that much of a problem as long as you are going on a non holiday weekend. Most people think you can just get right into the dunes, but that is not the case. They get very busy and the vouchers are the only way they can regulate how many people can get in as to not overdrowd the dunes.