Paint Sealant

On a new Toyota is the optional paint sealant really necessary. Is this a product I can purchase and apply myself? Car will be in South Florida. Hate to have to pay for the package that it's included with, ie: towing, car rental etc.
Would appreciate any input. Thanks

I've heard of this "paint sealant" that they put on the newer Toyota now, and I've had people tell me that they bought their cars new, and didn't have it on there, and they've drove the car around in really bad conditions, such as acid rain, road salt, and snow without washing the car regularly, and it was fine.