M'obeechi said:  "5. It doesn't even try to use the idea of a lever, which
 has been understood since at least Ancient Greece."

You're right! Instead, it uses the idea of the inclined plane, which has
been understood since at least Ancient Greece.

Inclined planes typically fit better under the seat of your vehicle than
 levers and fulcrums. : )

 Bottle jacks work o.k., their bearing point has always seemed to small for
my taste. No real great spot for that tiny point load under a van. Plus, as
 the van goes up and the angle changes, the bottle jack wants to tip over.
 Dangerous.

 I've always thought the simple design of the vanagon jack was devilishly
 clever.
 Don