With local production shutting down the big-car choices are getting fewer and fewer, but right now you can still buy a Calais if that's what you like. You can also buy an equivalent Falcon or Toyota Aurion. There are more expensive cars, from the likes of BMW, Mercedes-Benz and Audi etc. that would suit, but they come with a much higher price tag than a Calais. Others you could try are a Skoda Superb, a Honda Accord V6 Luxury if you're prepared to give up a little in size, and there's also the Chrysler 300C.

Orange peel was once a no-no for painters, it was thought to be a poor finish, but for some reason we've come to think that it means that lots of paint has been applied and it's now ok. There's nothing you can do about it without repainting the car. As for the scratching I would recommend regular polishing to give the surface maximum protection.