Blender is a free 3-D software that lets you create whatever model you want. Its difficulty is based on how well you know the hot keys. I like to use this program a lot with Garry's Mod to see how well I can make body armor or some kind of car part. I spend most of my time learning more about blender and what I can do with it.
1971 Buick Riviera GS- not as elegant as the 1963-1965 Rivs, but I've always had a place in my heart for the big boat-tailed ones. Remove the boat anchor 455 and replace with a nice LS7 and 6L90 6-speed automatic, slightly lowered, black tinted windows, killer stereo and appropriate wheels/rubber, that would make for a superb executive Hot Rod.