Nice BMW X1 site! How did they do it?

Nice BMW X1 site! How did they do it?

Check this out:  http://www.bmw.com.cn/cn/en/newvehicles/x/x1/2012/showroom/highlights/index.html#id=phase_exterieur

I didn't know jQuery can make such complex animation. How did they:
1 Merge cut images to be one image
2 Make the flying birds animation
3 Mouse wheel control
4 Interior & Exterior switch (click the arrow button at the right bottom cornor)

Any idea?