Anyone who voluntarily drives a car onto a beach is firmly in the 'numpty' category, even having a 4x4 is no guarantee of success. I would do it with a quad bike with nice fat tyres.
Best plan is....
A) never park on a beach, sand is tricky stuff and you can soon find yourself unable to get back off once the wheels have sunk in. Also by parking so close to the sea salt spray and the 'shot-blasting' effect of wind and loose sand will give your car a hard time. I used to work with a guy in RSA who parked on a beach and he needed new headlight glass, new windscreen and it took the paint off front of car bonnet etc.)
B) if you really must park on beach and you drive over seaweed / driftwood (the high tide line) to get to your spot then you are on the bit of the beach that belongs to the Queen (the bit between high and low tide mark) and at some time that bit of beach is going to be covered in water, seawater is very corrosive and will do your car no good at all.