File this one under Don’t Try This at Home.

Some DIY guys in Austin, Texas, with time on their hands and access to free equipment have demonstrated how to use an Apple (AAPL) iPhone to steer, accelerate and brake a jury-rigged car.

The video — complete with stunt driving and real-time collisions — is posted below the fold.

This is the third published video project from Waterloo Labs, a group of engineers from National Instruments (NATI), a manufacturer of embedded controllers and virtual instrumentation software.

In the first, Doug and Hunter taught us how to control fireworks with a computer. In the second, how to play first-person-shooter video games with real guns.

The third project is their most elaborate. The car — a late ’80s Buick — was purchased on craigslist for $300. The motors that control the accelerator and brakes were ripped from the power windows. The motor controller was borrowed from the FIRST Robotics Competition. The potentiometers, digital breakout board, analog input module, power distribution board, programmable automatic controller, wireless gaming adapter, Wi-Fi router, etc. were presumably supplied by their employer.

The iPhone app they wrote themselves.

Below the fold: Two videos, one showing what they did, the second how they did it.

[youtube=http://www.youtube.com/watch?v=_x5IziyOcAg]

[youtube=http://www.youtube.com/watch?v=EQaQFxWG8Ro]

For ten consecutive years since 2000, Fortune has named National Instruments one of the 100 best companies to work for in America.

Thanks to Seth Weintraub at 9to5 Mac for the tip.

[Follow Philip Elmer-DeWitt on Twitter @philiped]