According to the GREET model, the average conventional internal combustion engine vehicle (ICEV) is comprised of 61.7% steel, 11.1% iron, 6.9% aluminum, 1.9% copper/brass, 2.9% glass, and around 13.6% plastic/rubber.
By calculating the energy required to manufacture a specific mass of each material type, and then factoring the above percentages into the overall mass of a vehicle, we can get a reasonable estimate of the amount of energy that went into producing the vehicle.
Essentially the average car takes 69142 BTU/kg to build, an average hybrid takes 85209 BTU/kg. I've pulled these figures from
here.
You might just get away with it in a Prius' lifetime, when you factor in fuel costs.