If you've been following the Chevrolet Volt saga, you're probably familiar with the Cruze-based development vehicles GM has been using to test the electric car's drivetrain. But on Tuesday the Volt program took a major step forward with the completion of the first preproduction Volt prototype, complete with the final bodywork and chassis.

Known as "Integration Vehicle #1," the prototype has already been out and about on public roads, with high-level engineers like GM's Andrew Farah getting behind the wheel. GM says it will build 80 of the prototype for extensive testing over the next several months. The company recently noted it is actually ahead of schedule in this process.

"The mules demonstrated the potential drive experience of the Volt's chassis and powertrain, but the pre-production vehicles bring together the complete Volt experience into one dynamic vehicle," wrote Farah, Chevrolet Volt Vehicle Chief Engineer, in a blog post on the company's website.

"We're producing a few Volts per week now, but we'll quickly ramp up to 10 per week and will have approximately 80 pre-production vehicles built by October," he added. "By exceeding our own pre-production deadlines it allows us additional time to refine the vehicle."

In case you missed it, also check out our first drive review of the Cruze-based Volt mule: