how much costs?

I want to make my nissan like this one (http://seeit.110mb.com/index.php?gallery=Nissan%20Wallpapers%20-%20Nissan%20Sports%20Coupe%20Concept%20Car)

If you're talking about 1:1 then you're in the wrong section. Try here:
http://www.automotiveforums.com/vbulletin/forumdisplay.php?f=763
Or if someone else knows exactly were to ask about custom 1:1 body kits please post the link. (I mostly only use the modeling section:rolleyes: )

If you're talking about scale models then...
Are you asking for someone to make a custom build?
Are you planning to mod a kit? If so, which kit are you planning to start from or are you planning to scratch build?

Give us more details to get a better answer.
And welcome to AF!

Steve