3 cars in 27 years or so driving isn't too bad, first 2 were pre-airbag anyway. Yeah, I don't understand how don't get all messed up, use to ride a motorcycle, before cars. Had several close calls with the grim reaper, and just walked away. I'm really a 'safe' driver, don't do crazy wreckless stuff, drive a little fast sometimes, but depends on traffic and road conditions. It's usually the other drivers that cause the problems. One car turned out good though, a '79 Ford Fiesta, only made them 3 years. I paid $200.00 for it, got side swipe by a tourist from brazil, rental car company wrote me a check $1635. I beat on it with a hammer for about a week, used about a dozen coat hangers, some plexiglass and drove it for a little while. A little tough to steer straight, weird sounds... Sold it for $200.
Seriously though the ultrasonic range project kit is on several sites, somebody probably put up a copy of the schematic some place. Probably find it with robotic stuff too.
Oh, just curious... Did your friend get friction damage from the airbags? I've only talk to three people who had airbags deploy, all had some raw skin. Just curious if this normal, just seems like it. One woman was in a Walmart parking lot, major low speed wreck, little bumper damage...