Whats all this? Wut do you mean?

I want to be a car designer someday and was hoping if anybody has any advice on making cars in sketchup. I alredy make cars but was hoping to improve. http://sketchup.google.com/3dwarehouse/search?tags=Ray+Ochoa&scoring=d My 3 latest cars have a render animation. If you want to see it just click on the logo next to the picture . Theese are the urls for the animations http://www.youtube.com/watch?v=y9qraxilOhQ&fmt=18
http://www.youtube.com/watch?v=hm-2cauo_Bk&feature=user&fmt=18
http://www.youtube.com/watch?v=1nlgkq_jgt8&fmt=18

I want to be a car designer one day. I currently use sketchup and i have rendered my cars with both Podium and Kerkythea. Do you have any advice on any other rendering program for sketchup i should try? This is the link for my cars on the warehousehttp://sketchup.google.com/3dwarehouse/search?tags=Ray+Ochoa&scoring=d

All these renderings look professional. I'm just a kid but wanted to know. Can you make business with render of 3d models?