It takes a lot of skill to wet sand a car so uniformly, and you wouldn't need 1000 grit to do it. I wouldn't go any further than 2000 grit. But then you need to know how to properly buff it out when you're done so as not to burn through the paint, especially along the edges.

I know really high end detailers who would actually charge more than $2500 to fully wet sand and buff out a car. Achieving this look with vinyl is far less invasive to the paint, especially factory paint, than sanding and buffing. It's also far, far less expensive than a proper paint job to get the look, and even less expensive when you then consider the cost of a second paint job to return it to a stock look.