Hdri map problems for car renders

Hi! :smiley:

Some weeks ago I finished my Lamborghini Gallerdo model and since then I’ve been working on rendering some nice images with it. :slight_smile:

But I have some problems… First of all I didn’t knew anything about Hdri lighting, but I gave it a try some days ago and I ended up with some problems… I found this Hdri preset .blend file made by this guy: https://www.youtube.com/watch?v=8l517BiA8Qw#t=55 but when I render my model, all edges become jagged, like when you are playing a game without Anti-aliasing… :confused: Posted some of my render in this post: http://blenderartists.org/forum/showthread.php?348370

Another thing is that I cant make the plane the car is placed on fade in with the hdri background… :frowning:

Thanks :slight_smile: