[NYT] "The Dozens of Computers That Make Modern Cars Go (and Stop)"
By JIM MOTAVALLI
Published: February 4, 2010

The electronic systems in modern cars and trucks - under new scrutiny as regulators continue to raise concerns about Toyota vehicles - are packed with up to 100 million lines of computer code, more than in some jet fighters.

“It would be easy to say the modern car is a computer on wheels, but it’s more like 30 or more computers on wheels,” said Bruce Emaus, the chairman of SAE International’s embedded software standards committee.

Even basic vehicles have at least 30 of these microprocessor-controlled devices, known as electronic control units, and some luxury cars have as many as 100.(...)
source and further reading:
The Electronic Systems That Make Modern Cars Go (and Stop) - NYTimes.com